Entangled States
by Tenebrielle
Summary: An accident causes Bruce Banner and Tony Stark to switch bodies, leaving them to struggle with the other's "terrible privilege" until they can find a way to reverse the change. But the stakes might be higher than either Bruce or Tony realizes… Science Bros friendship, with a liberal dose of Clint.
1. Chapter 1

_**A/N**: Hello everyone! _ _I'm finally back after a much-too-long fanfic hiatus. Kudos and many many thanks to RedTigress of The Beta Branch for the prompt that inspired this story, beta reading (along with VleRoux), and for the lovely cover art. Entangled States is rated **T** for language and thematic elements. Additional **warnings** will be added to individual chapters as needed, in the author notes. I'm going to try to update regularly (about once a week), but there is a chance work will get in the way and I might not be able to keep to that schedule...I'll try! :) I hope you guys enjoy the story!**  
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**Entangled States**

Chapter 1

In retrospect, Clint should have known something was going to go terribly wrong. The mission had been more or less routine, at least as routine as things ever got with the Avengers. Portal opens in the sky. Aliens fall out of portal. Aliens cause chaos. Cue the Avengers.

The aliens themselves had been a pain in Clint's ass. Everyone's, really. They were vaguely insectoid and used some sort of weird energy weapons that Stark and Banner got all excited about. Clint didn't really bother with the details; he didn't really care what the things were or where they were from. Once the shooting started all he cared about was how to kill them.

Unfortunately they were armored heavily enough that Clint's arrows just glanced off unless he hit a crack or a joint, which meant they were more or less bulletproof (inconvenient for Natasha) and able to withstand all but the most direct blows from Rogers' shield. Even that didn't pose too much of a problem: the archer picked them off through gaps and eye slits and let Natasha and Steve finish them off hand-to-hand. Stark just swooped around blasting everything in sight. He was aided by the Hulk in causing as much mass destruction as possible. They let the assassins and Rogers finish the clean-up. Well, that was certainly mission-typical.

There hadn't been any movement for about half an hour, so Clint decided it was safe to shimmy down from his perch. A SHIELD cleanup team was due any minute, so now they were just waiting on Banner to de-Hulk. He strolled towards Natasha and Rogers. Stark landed near them with a metallic _clunk_ of armor. Barton yawned and pulled his bow up across his shoulders. He draped an arm over either end and twisted from side to side to stretch his back. It felt good to move after being stuck up on that tower for so long.

He watched as the Hulk finally slumped to the ground a little way away. It was always weird to see the green monster go so quiet and still as Bruce fought to bring himself back to the surface, Clint thought. Slowly, the green began to fade and the Hulk began to shrink. Clint glanced at his watch with approval. Banner was really getting better at managing the transformations. The archer considered going to run the preflight checks on the jet. If they got a move on, he might just be able to catch the tail end of the game. That'd be nice, especially with a cold beer or three-

"Live one!" Stark suddenly yelled. "We've got a live-"

Clint's head snapped up. Stark's AI must've picked up a straggler. His eye caught a flicker of motion in the darkness and his bow was instantly in his hands. He reached for an arrow, drew it back, and let it fly in one smooth motion. The shot was good; it hit the alien right under the arm. Instead of going down, though, the insectoid figure staggered and raised its other arm. Something purplish glowed in its hand. Oh shit the thing had a _grenade_-

Another motion caught Clint's eye even as he raised his bow for a second shot. Somewhere not far from the alien, a pale human form moved in the darkness and he swore under his breath. Christ, Banner had picked a really bad moment to come around. The glowing grenade left the alien's hand in the same moment Clint got the second shot off. It flew towards them but he could tell by the trajectory there was no way it would reach the group. But Banner, Clint suddenly realized, was between the alien straggler and the Avengers. The weapon was headed right at him.

"STARK!" the archer bellowed, but Tony was already in motion. Iron Man streaked overhead towards the pulsing light, grenade, whatever it was. Bruce was still struggling groggily into a crouch, unaware of the peril he was in.

"Banner, move!" Steve yelled, but it was too late. Behind him, Natasha swore viciously.

Stark's metal fingers snatched the alien grenade out of the air. Somehow he had the presence of mind to catch himself with his stabilizers in mid-air and slow down so he wouldn't injure the scientist when he inevitably collided with Banner. The light pulses coming from the grenade rapidly increased in frequency; the fuse indicator, Clint realized. He could see Tony didn't have time to chuck it away. So could Tony. Stark rolled himself between the unarmored Banner and the grenade and clutched it to his chest-

The alien weapon exploded with a brilliant flash of light. Violet energy crackled over Stark and Banner, arcing between metal armor and bare skin. Tony howled over their earpieces, and Clint thought he could hear Banner yelling too. A moment later, the energy had dissipated. He blinked frantically to clear the bright spots from his vision. Stark and Banner were in a tangled heap on the ground. Smoke rose from the remains of the grass around them.

"Stark!" Steve cried. "Banner!"

"Shit," Clint breathed, slinging his bow over his shoulder and sprinting towards the fallen pair. Natasha was hard on his heels. Rogers, of course, got there first.

Steve dragged Banner out first. He held his ear close to the unconscious scientist's face. "He's breathing, anyway," he reported.

Clint dropped into a crouch beside Bruce while Steve checked on Tony. He pressed a couple of fingers to Banner's neck, feeling for a pulse. Satisfied that the scientist was alive and not going green, he fished an ultrathin emergency blanket from one of his pockets and draped it over Banner's mostly-naked body. A few burns marred the scientist's bare skin, but nothing looked life-threatening. Clint glanced over at Steve and Natasha, who were leaning over Iron Man. "Stark?"

"Alive," Steve said. He'd popped Tony's faceplate and dropped it to the ground beside its owner. The arc reactor flickered once or twice but seemed to stabilize within a moment. JARVIS was still working then, Clint thought. Steve glanced up at him. "I guess we won't know more than that until we can get his armor off."

Clint rocked back on his heels. "Funny, I thought his armor would protect him from energy blasts. I mean, he can take a hit from _Thor_ without any problems."

"And doesn't Banner usually Hulk-out from this kind of thing?" Steve asked. "When he gets hurt?"

"Must be something different about this tech," Natasha observed. She nudged the billionaire impatiently with her foot. They couldn't leave until they had enough help to move Stark in his heavy armor, or until he woke and could move under his own power. "Wake up, Stark."

Nobody was expecting Tony to actually wake. "Ow," Stark groaned and they all jumped. His bright brown eyes flickered open and darted from side to side. He looked…confused, Clint thought. "What…? Did I hurt anyone?"

"Welcome back," Steve said. He looked a little surprised by Stark's odd words, but relieved nonetheless.

Tony's eyes widened. "What?" he started, looking thoroughly lost. He blinked several times. "I'm not naked."

Stark reached for his head, but stopped partway and stared at his hand like he'd never seen it before. He waggled the gauntleted fingers experimentally. "Why…why am I not naked? How did I get in here?"

"Tony," Steve started. His expression had gone from relieved to alarmed. "Are you-"

"What is this, some kind of joke?" Stark interrupted. He levered himself awkwardly into a sitting position. There was a note of panic in his voice that bothered Clint. "Tony's idea? Tranq me and stuff me in his suit?"

"There's no prank, man," Clint said. Stark's eyes found him, and the sniper was surprised to see fear in them. "You got zapped by some weird alien thing, Tony. We better get the medics to check you out-"

"I'm not Tony!" the billionaire exclaimed. There was a plaintive note in his voice. "This really isn't funny, guys…"

Natasha's eyes narrowed. "What do you mean, you're not Tony?" she demanded.

Iron Man was struggling to his feet now. There was a weird, almost uncoordinated sense about his movements that reminded Clint of a puppy or a foal or something trying to learn to walk. The hell was going on?

"I'm Bruce!" Stark cried. "Bruce Banner! Why are you guys calling me Tony?"

Steve rolled his eyes. "Knock it off, Stark," he growled, sounding exasperated. "Look, Bruce is over there." He pointed at Banner's unconscious body.

The blood drained from Stark's face. His mouth worked but no sound came out. Clint looked from Steve to Natasha, confused. He couldn't remember ever seeing Tony Stark speechless before. Natasha's eyes were narrow with thought. Steve just looked irritated.

"But…how can I be over there if I'm here?" Stark (_Stark?_) sounded truly panicked now. He tried to take a step back and seemed to stumble over his own boots. He reeled a bit before regaining his balance. "I'm here. But there…what? It's not possible!"

Natasha figured it out first. "Oh, you have _got_ to be kidding," she exclaimed. She turned to Tony. "What's Betty's birthday?"

"Tash?" Clint questioned her, but she shot him a _look _and he obediently shut up.

"June 14," Stark said without hesitation. Clint froze. There was no way in hell _Stark_ would know the answer to that question. He couldn't even remember his own girlfriend's birthday, let alone Banner's ex. So that meant-

"That's not Stark," Natasha said, folding her arms across her chest.

"Of course that's Stark!" Steve snapped. "_Look at him._"

For answer, she pointed at Stark. "No, that's Banner," she said simply. She pointed at Bruce's body on the ground. "That's Stark." She shrugged. "Somehow they seem to have switched bodies."

There was complete silence for a few beats while Clint and Steve processed that information. They spoke together.

"_What_?" Steve exclaimed.

"What do you mean_ switched bodies_?" Clint demanded. The _hell_ was going on? He had to admit that it made some sense…especially with the way Stark was disoriented and stumbling around. That he somehow knew Betty Ross' birthday. But come on, _switched bodies_? That was just insane.

Stark (_Banner?_) looked around uncertainly. "I'm Bruce. My consciousness, Bruce's, I mean, is here in Tony's body. I'm assuming that Tony's in my body right now," he explained. "At least that's what I think happened."

"How is this even possible?" Steve asked. He sounded completely bewildered. He took a step forward and peered closely into the scientist's face, as if to see the change.

Bruce took an instinctive step backwards. The _whir_ of the servos in the armor seemed to startle him and he glanced nervously from side to side at the plates covering his shoulders. "Uh, wow, I'm not used to being at eye level with you, Steve."

Clint stared. Now that he thought about it, he sure didn't sound like Stark. Something about the speech pattern or something was just off. He didn't act like Stark either. "That is _weird_, man. You sound like Tony but…not."

"A very astute observation, Barton," Natasha said with more than a hint of sarcasm. Clint shot her a dirty look. What was she all worked up about? Worse things had happened on missions.

"You're telling me," Bruce said dryly. He picked up the faceplate from the ground and turned it over in his hands to avoid looking at anyone. Clint got the impression he was trying very hard to keep his cool. Well, if anyone was good at that, it was Banner. "Um, am I…is Tony…?"

"He's got some burns, but he's more or less unhurt. Should probably get him checked out back at base," Natasha said. She shot the scientist a quizzical look. "How do you feel?"

Banner's eyes kept flicking down to his body on the ground. He looked thoroughly unnerved by the sight, but he couldn't seem to avert his gaze for long. "Uh, tingly."

"Tingly?" Steve exclaimed. He looked like he needed a drink, Clint thought. The archer smirked.

"Yeah," Bruce said with another shrug. "And everything tastes like…coconut." He made a face. "I hate coconut." He smiled sheepishly, and in that moment it finally sunk in for Clint that it really was _Banner_ in there. Tony Stark didn't do _sheepish_. "What happened exactly?" the scientist asked him.

"We missed a goon," Clint said with a shrug that looked a lot more nonchalant than he felt. He was kicking himself mentally, and he was pretty sure Rogers was doing the same. "Threw some kind of energy grenade at you; Stark grabbed it but it went off before he could get rid of it. He tried to protect you from the worst of it."

"I guess that's debatable," Banner quipped. He still sounded nervous, but Clint thought the fact that he could attempt to make a joke out of his bizarre situation was encouraging. The archer smirked again, and the corner of Rogers' mouth twitched reluctantly.

Natasha, however, was not amused. "What about the Hulk?" she asked coolly, but Clint could hear tension in her voice. So that was what she was worked up about. He hadn't even thought about the Big Guy. He trusted Banner to keep a handle on that.

Banner paled, the skin whitening around Stark's dark beard. Clint felt his gut twist unpleasantly. That was not a good reaction.

"He's…not here," Bruce exclaimed, sounding stunned. He glanced rapidly between his teammates. "I didn't notice before, but he's not here. He's…gone." His bright eyes flicked downward to the unconscious physical body of Bruce Banner, now occupied by Tony Stark. They widened suddenly in understanding. "Oh _god_. You guys might want to, uh, move back."

It took Clint a second to understand what Bruce was saying. "You mean _he's _in there? With _Stark_?"

Banner cringed. The movement looked ridiculous in the Iron Man armor. "Uh, yeah, I'm afraid so."

Natasha took a hasty step backwards. Steve had that look of pained responsibility that he always got when faced with the prospect of dealing with a miserable situation. Clint just swore under his breath.

So much for a routine mission.

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_To be continued! Please review; I love hearing from readers. :)_


	2. Chapter 2

**_A/N:_**_Wow, I'm a little overwhelmed by the enthusiastic response to this story! You guys are awesome! Thanks much to everyone who favorited, followed, and especially reviewed. I really appreciate all the love. :) Many thanks also to RedTigress and the Beta Branch for beta reading and helpful suggestions. I should mention that POV is going to switch around in no particular order throughout the story. __ On to chapter 2!_

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**Entangled States**

Chapter 2

"Wait, the Hulk is-" Steve stopped mid-thought, looking horrified by the prospect of Tony trying to control the Hulk.

Natasha said instantly: "Tranq him, Clint."

Clint didn't move. He glanced at Bruce. "We shouldn't, not while he's unconscious," Bruce said hastily, fearing for his body. When he spoke it was Tony's voice and it sounded unfamiliar in his ears. He suppressed a shudder and tried to focus on Steve. "He could slip into a coma."

Steve pulled himself together. "Banner, what are we looking at here?" he asked Bruce with a resigned sigh.

Bruce looked around uncertainly at the group. "Uh, to be honest? I'm not really sure. I don't know how the Other Guy is going to react to a different…consciousness."

"This is going to be a disaster," Natasha said, folding her arms across her chest. "I say we tranq him and deal with it later."

"I'm not sure that's necessary, Natasha. I think Tony is stubborn enough to keep the Other Guy in check," Bruce told her. His bright eyes flicked between his teammates, assessing their reactions. "It's mostly a matter of willpower and Tony's got that in droves."

"Sure he does," Clint muttered. "When it suits him."

"Bruce, it took you _two years_ to learn to control it at all," Natasha snapped. Bruce winced inwardly. Despite the fact that they had been working together now for some time, she'd never really gotten over her fear of the Hulk and it was beginning to show.

"She has a point, Banner," Steve said. The words stung, but Bruce had to admit he was right.

"I didn't have anyone to help me through it," Bruce replied evenly. "I think I can talk Tony through the process if it comes to that. But we don't know it will. The Other Guy had a good run tonight; he should be pretty quiet for a while."

"We still have to get back to New York!" Natasha exclaimed. "We can't risk having Stark in the tower like this-"

"_Guys_," Clint interjected sharply, before Bruce could make a retort. "He's coming around."

To say Bruce was disconcerted to see his own body lying on the ground was an understatement, but it was even weirder to watch his own eyelids fluttering as Tony began to wake.

"Ouch," Tony moaned. His eyes, _Bruce's eyes_, finally opened. He blinked several times, looking disoriented. "What the?" He took a breath and froze with surprise. His hands flew instantly to his chest, feeling around for an arc reactor that was not there. "What the _hell_?" he exclaimed, looking up at Bruce.

"There's been an, uh, accident," Bruce told him nervously.

Tony's eyes widened as he recognized his own face, surrounded by his armor, looking down at him. He stared incredulously for a moment before saying: "Holy sh- _is that you?_"

Bruce gave him a faint smile. "Yeah."

Tony blinked rapidly several times. "So we-?"

"Yeah."

"How the _hell_-"

"Sounds like it was some kind of energy pulse," Bruce told him with a shrug.

"Glad we made that clear," Steve grumbled to Clint, who smirked. Natasha's pursed lips deepened into a genuine frown.

"The grenade," Tony mused. So far, he was taking the news pretty well, Bruce thought. He flung the emergency blanket out of the way and scowled. "Hey, what did you do to my suit?"

Tony jumped to his feet and stood on his toes (Bruce was already shorter than Tony, and in the armor he was taller than Steve) to get a look at the damage to the helmet. "Again with the faceplate! Goddamn it, Rogers, there's a release," he shot over his shoulder at the soldier. He stabbed Bruce's glowing chest with a bare finger. "You, bend," Tony ordered and Bruce obediently crouched. Tony fumbled with something that made clicking noises around his neck and wrestled the Iron Man helmet from his head. "Give me that. See if I can mitigate the damage Captain Failure did."

Tony plucked the faceplate from Bruce's hand and frowned down at it. The physicist glanced at Steve, who looked embarrassed. Clint looked like he was trying not to laugh, and Natasha just looked fed up.

"Pants, Tony," Bruce sighed. "I'd like to at least try to maintain some shreds of dignity, if possible."

Tony glanced up from where he was squinting (Bruce's glasses had been left onboard the jet) at the Iron Man helmet. He raised his eyebrows rakishly at the scientist. "Nothing we haven't all seen before, Banner."

"_Tony!_" Bruce groaned, feeling his cheeks redden with embarrassment. He could hear Clint tittering in the background. The scientist glared at him.

Clint guffawed once more before making a valiant effort to retreat behind one of his neutral agent expressions. "Sorry, man, but you gotta admit he has a point."

"Just do it, Stark," Natasha snapped at him. Bruce eyed her with dismay. She was trying to hide it, but she looked very, very tense. He resisted the urge to sigh again. He and Natasha were finally on decent terms, but she still wasn't very keen about the Other Guy. It had taken him months to get her to even get close to trusting him. Now it looked like Tony had reawakened all those old fears. Fantastic.

"As you can see, Romanoff, my hands are full. Unless you're volunteering…" Tony said without looking up.

Natasha's eyes flashed malevolently, but she said nothing. Clint laughed again and she shot him a scathing look. "What? It's just really funny coming from _Banner_!" the agent grinned.

Bruce grimaced and hid his face behind one of his armored hands. Steve was looking between the two of them while Tony fiddled with the faceplate. "I have no idea how I'm going to explain this to Director Fury-"

The physicist felt his heart leap into his throat. No. They couldn't tell Fury about this; it _would _be a disaster. A disaster filled with mutual mistrust and cages-

"No!" he exclaimed, only for Tony to say the same thing at the same time. They looked at each other in surprise for a moment, before continuing once again at the same time.

"You're not," Tony said flatly.

"There isn't going to be any explaining, Steve," Bruce said over him.

The solider looked annoyed. He didn't like it when they bent rules, and not informing Director Fury of their…problem probably broke about forty regulations. "But-"

"SHIELD does _not_ need to know about this little mishap," Tony added. "Banner and I can figure it out. We don't need any interference."

Clint's expression was determinedly neutral, but Natasha looked downright mutinous. Bruce hoped she'd let them at least discuss the issue properly before taking matters into her own hands. "Fine. We'll talk about it later," Steve amended, with a wary glance at Tony. "Let's focus on getting home for now. Can you fix the helmet, Stark?"

The billionaire in Bruce's body didn't seem to notice the tension between his teammates, and Bruce hadn't noticed any outward signs that his friend was troubled by the Other Guy. He wondered if they could risk taking him in the quinjet. Getting home was going to be a pain if they couldn't.

The mask clicked in Tony's hands. "I think this'll do it," he announced. To Bruce's relief, he had hitched up what was left of his trousers. "Push down until it clicks twice. Not great but it should get you home."

Bruce accepted the mask gingerly with his clumsy gauntlets. He fumbled the helmet once while trying to put it over his head. Finally, it clicked into place. He jumped when the faceplate ground down automatically with the squeal of abused metal.

The HUD flared to life instantly, nearly dazzling the physicist_. "Welcome back, Mr. Stark,"_ JARVIS' cool voice was in his ears.

"Uh, actually I'm Bruce Banner," Bruce told the AI. "It's…complicated."

He thought he could hear a bare trace of surprise in the AI's response. _"Very well, Dr. Banner. Readings from the arc reactor are holding steady now but I am detecting some minor damage to circuitry between the suit and the arc coupling, as a result of the electrical pulse. May I recommend not throwing yourself on alien weapons in the future?"_

Bruce blinked. A schematic of the armor popped into view to one side, with power level readings and damage reports. Brilliant green circles flared to life around his teammates as his eyes flicked between them. He blinked again and the display magnified Steve's shield to alarmingly large proportions. Bruce jerked his head back instinctively before he realized that the display wasn't going anywhere, and it was a useless gesture. A row of icons popped up along the bottom of the HUD and Bruce flicked his eyes towards one that resembled a magnifying glass. His field of vision zoomed out and expanded again. Now he could see Tony's (well, his own) mouth moving and realized that the external microphones must be off.

"Uh, why not," he said absently. "JARVIS, I can't hear Tony. Can you fix that, please?"

An instant later, he could hear everything occurring outside the mask. Readouts on all of his teammates' vitals and other information were flooding his display. They seemed to change every time Bruce moved his eyes. It was a veritable flood of data and Bruce couldn't help feeling a bit overwhelmed. "While you're at it, can you pare these alerts down to the bare minimum?" he added.

"Banner?" Tony was saying from outside. He rapped on the mask with Bruce's bare knuckles. "Banner? You okay in there?"

"Uh, yeah," Bruce said. His voice, _Tony's_ voice, sounded a bit dazed. The rush of data was exhilarating in a way, and the somewhat vain academic part of his brain relished the challenge of taking it all in. "It's…great."

Tony smiled knowingly. "First hit's free."

Clint guffawed again and Bruce himself chuckled. Tony was looking up at him expectantly. "Uh, looks like there's some electrical damage caused by the power surge, but nothing too bad. Arc's acting up a little, though. JARVIS says it's not a problem."

Tony's bare shoulders bobbed in a shrug. "It'll wait until we get home. But Banner, if you go green in _my_ suit, so help me, you _will_ put every damn piece back together."

Bruce winced behind his mask. Right. Somehow he had to break the news to Tony that _he_ was going to have to deal with the Other Guy for the foreseeable future.

"JARVIS, how do I raise the faceplate?"

"_Left chin button, sir."_

Bruce nudged the button and the faceplate ground reluctantly backwards. He exchanged anxious looks with Steve and Clint. Natasha seemed to want no part in the impending conversation. Her fingers toyed nervously with the butt of one of her pistols. Steve nodded at him, and Bruce glanced to Clint for confirmation before plunging forward. The archer's bow was back in his hands. He shifted his position so he had ready access to his quiver.

"Tony," Bruce said calmly. He waited until the engineer looked up before continuing. "There's something you need to know. The Other Guy. He's, uh, not in here with me."

"Of course he's not, otherwise you wouldn't be wearing my-" Tony froze mid-quip. His soft eyes widened with shock. "What? You mean he didn't- Oh. _Oh._"

He put a hand to Bruce's graying head and winced. Bruce instantly recognized the symptoms and muttered a curse. So much for this not ending badly. Perhaps he shouldn't have said anything at all. "Run," he shot over his shoulder at Clint, Steve, and Natasha. "Get as far from us as you can."

"Is that him?" Tony asked with forced calmness. His face had gone very white and there was a flicker of fear in his eyes.

Bruce swallowed hard. He had hoped Tony would be spared this. "Yes, that's him," he confirmed, forcing his voice to remain even. He still might be able to talk Tony through the process of resisting the transformation. "He's going to try to push you aside. Tony, you need to focus on keeping yourself in front. Focus on breathing first, then focus on pushing back."

"It-ahh," Tony grimaced. He squeezed his temples in a weirdly familiar gesture. "He's…stronger than I thought."

Bruce risked a quick glance over his shoulder. Nobody behind him had moved. "Get out of here!" he yelled at them. Finally, Natasha grabbed Clint's arm and started dragging him away.

Steve hesitated. "But we can't just leave you-"

"Go, Steve!" Bruce snapped, not taking his eyes from Tony. The soldier always picked the worst moments to try to be noble. "Trust me on this!"

Steve took off after Clint and Natasha. Tony fell to his knees with a loud groan, clutching his head, and Bruce couldn't worry about them any longer. Bruce dropped to the ground with him and grabbed at his wrists. He tugged them away from Tony's face. He had to be careful not to accidently crush his own bones with the gauntlets. Bruce shuddered at the thought.

"Tony. Tony! Look at me!" he said loudly. Stark looked up and _god_ it was _weird _to be looking into his own dark eyes. Even without JARVIS' help, the physicist could see Tony was starting to hyperventilate. "You can still stop it, Tony. You _are_ stronger than he is! Push him back!"

"Aaah," Tony moaned. His body convulsed in Bruce's grasp. Tony curled in on himself. His hands balled involuntarily into fists. Bruce adjusted his grip, struggling to keep him upright. "Never said how…much this…hurts."

"I know," Bruce told him grimly. "Keep your focus. _You_ are in control. Don't let him push you aside."

Bruce knew it was a lost cause even as he tried to encourage his friend. His muscles were beginning to quiver and swell; the familiar green tinge spread over his skin. Even Bruce, with all his practice, would have had a difficult time stopping the transformation now. Tony was at the point of no return. He was going to transform and there was nothing Bruce could do about it.

"Can't. Can't hold…" he gasped at Bruce. His eyes squeezed shut again with pain. "Did…they…?"

Bruce suddenly realized he was asking about the others. Tony had been trying to hold it together long enough for them to get away. The scientist couldn't turn his head very far in the armor, so he had to rotate his entire torso to look over his shoulder. Steve had stopped nearby (_idiot!_ Bruce thought angrily); Clint and Natasha were still running.

"Yes, Tony, they're clear." Bruce released his wrists so he wouldn't accidently injure his friend and began to back away. "It's going to be okay," he said desperately. He felt like he was babbling but he didn't know what else to do. "Tony, it's going to be okay. Just…let him out now. You'll be okay."

Tony had time to shoot him one last desperate look before he sagged to the ground and let the monster out.

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_Please review! I love hearing from you guys, and I try to write back. :)_


	3. Chapter 3

_A/N: Wow, I still can't believe the enthusiastic response to this story! Many thanks to everyone who followed, favorited, and especially reviewed! They've been great writing motivation. :) Also thanks to RedTigress and VleRoux of the Beta Branch for their beta reading and general awesomeness. On to the chapter!  
_

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**Entangled States**

Chapter 3

Bruce watched, transfixed with horror, as Tony's body swelled and turned green. His scream of pain choked and deepened into a loud roar. Bruce couldn't tear his eyes away. He felt sick. He had never truly _witnessed_ the transformation take place before. Video didn't count, not for something like _this_. God, no wonder Natasha had been so terrified of him.

"_Banner, get out of there!" _Clint's voice crackled in his ears. Startled, Bruce looked around for the archer before he remembered that he was connected to the comm system now. He usually wasn't. The Other Guy and earpieces just didn't work.

JARVIS brought the faceplate down. The armor would protect him to some extent, but he didn't really want to find out how well it would stand up to an angry Hulk. Bruce hastily began to back away again. He had seriously overestimated his mobility in the armor. He focused on trying to not trip over the cumbersome boots. No wonder Tony flew everywhere; walking was _hard_.

"_Hawkeye, you have a shot yet?"_ Steve's voice asked.

"_Not till he's done transforming,"_ Clint replied. He was breathing heavily; still running, Bruce thought. _"I'm gonna try to get a little more distance." _

"_Watch it, Banner!"_ Steve shouted.

Bruce looked up at the warning and felt his eyes widen with terror. The Hulk loomed above him, glowering down with malevolent green eyes. The physicist froze instinctively. It was beyond surreal to be _facing_ the monster; almost as surreal as it had been to see his human body lying on the ground. His mouth went dry as the Hulk threw back his head and roared. The noise was deafening even after JARVIS had the sense to mute the external mics. He was so close that the sound waves rattled the armor and vibrated deep in Bruce's chest.

Cold sweat broke out over his body. He took a deep breath and let it out slowly. Despite his fear, Bruce knew he had to try to face the monster down. There was a chance the Hulk might recognize Iron Man as a friend. Maybe he could at least spare Tony the trauma of waking up with fractured memories of trying to kill his teammates. Bruce swallowed hard. His memories of Tony trying to calm the Other Guy were practically nonexistent. He'd have to make it up as he went.

Bruce forced himself to hold his ground. "Take it easy," he said aloud. His voice, Tony's voice, was choked with uncharacteristic nerves. The Hulk eyed him, his huge head cocked suspiciously to one side. Banner spread his arms wide in a nonthreatening gesture and tried to sound more like Tony. "C'mon, big guy, you know me."

The Hulk roared in response and lunged at Bruce. The physicist panicked and tried to dodge the green fist, but the thrusters didn't kick in right and he landed ungracefully on his face. Steve and Clint were both shouting over the comm. Bruce was more concerned with the massive green fingers that had just seized his leg. His own armored fingers raked furrows in the turf as he was hauled backwards.

The scientist yelled as the Hulk dragged him upside down. The metal armor groaned and popped in protest. Angry red warnings with words like PRESSURE WARNING and FAILURE IMMANENT flashed across his HUD. Voices howled warnings in his ears and his stomach lurched as he was swung violently upward. Bruce suddenly realized what was going to happen. The Hulk was going to slam him into the ground at full force.

Tony would _murder_ him if Bruce let the Hulk trash his armor, let alone his body. Thinking fast, the physicist flexed his ankles downward to ignite the thrusters. The monster roared with pain and frustration as superheated gas burned his skin and sent Bruce tearing out of his grip. He accidentally cut the thrusters too soon and tried to fire his repulsors in time to compensate, but it was too late. Bruce hit the ground in an ungainly heap and skidded several meters across the grass. The back of his head slammed into the metal of the helmet and he saw stars.

"_Banner, move!"_ Clint shouted over the comm.

Bruce struggled to his knees. "JARVIS!" he cried desperately, raising a gauntlet and twitching his fingers backward to fire a repulsor blast at the Hulk. The monster was almost upon him. Bruce fired again at higher power and with both hands, trying to hold him back until Clint could bring him down. "I need options!"

"_Barton, what are you waiting for?_"Steve yelled, forgetting radio protocol in the heat of the moment.

"_Goddamn quiver's jammed!" _Clint snarled. An electronic whine screeched over his communications link, interspersed by a string of profanities. _"I need another minute." _

The word HULK flashed across Bruce's display in transparent green letters. A set of several icons flickered to life around it. One of them resembled a firework, another resembled a speaker. Bruce didn't have time to try to interpret their functions. "Pick one!" he shouted at the AI.

"_Deploying flares," _JARVIS' cool voice replied. The firework icon turned from red to green. Bruce's HUD exploded in brilliant flashes of light until the filtering kicked in and he could see again. The Hulk howled and rubbed at his eyes. He began to beat the ground around him blindly with his fists. Bruce scrambled away as best he could. Several pieces of the armor on the schematic display flashed orange in warning. Apparently the armor was less Hulk-proof than he'd thought.

"JARVIS, get us up in the air. Display the power balances so I can get a feel for what you're doing," Bruce ordered. He felt the armor snap into alignment of its own accord. The HUD flashed and rearranged itself to display flight controls. The thrusters in his boots kicked off and he streaked upward at incredible speed. He couldn't help letting out a _whoop_ of surprise and excitement. JARVIS banked left and brought them around in a circle well above the Hulk. Bruce laughed with unexpected delight. He couldn't believe it. He was flying!

"_Heads up, Hawkeye! He's coming for you!" _

The thrill of flight faded instantly with Natasha's warning. The Hulk had lost interest in Iron Man and had spotted Clint nearby, where he was struggling with his malfunctioning gear. He lumbered towards the archer with a menacing growl. Bruce was out of range for a repulsor blast and he didn't dare use any of the guns for fear of injuring one of his teammates with ricocheting bullets. Before Bruce could do anything about it, a flash of red, white, and blue darted towards the Hulk and Barton.

"Don't, Steve!" Bruce warned, but it was too late.

A metallic _clang_ rang out as Steve's shield bounced off the back of the Hulk's head. "Hey!" Steve's voice bellowed. He easily caught the shield and stood his ground.

The monster rounded on Steve with a roar and lunged for the soldier. Steve nimbly dodged the green fist. He brought his shield down on the Hulk's knuckles and leaped backwards, trying to draw him away from Clint. The monster roared louder and stormed after him, grabbing for Rogers with both hands.

"_Cap, back off!"_ Natasha's voice interrupted. _"Watch it, he's-"_

The physicist's eyes darted to Steve's position on the ground and he swore under his breath. Instantly, he could see the soldier was in trouble. He had underestimated the Hulk's reach. A green fist was already swinging towards him. Rogers realized his mistake too late and tried to bring his shield up to protect himself-

Bruce watched in horror as for the second time that night, things went from bad to worse.

WHAM. A huge green fist impacted with the shield and sent Steve flying head over heels. The soldier crashed into Clint, who was finally lining up a shot and couldn't dodge in time. The edge of his shield connected soundly with the archer's head. Clint crumpled to the ground. Rogers sprawled on top of him. His arrow streaked uselessly upward into the sky. Even from the air Bruce could see blood running down the archer's face. He felt his heart clench.

One of the little yellow icons on his display became a large orange X. The text above it read: "HAWKEYE: INCAP'D." Bruce glanced at it and the associated vitals popped up. Barton was alive, but definitely unconscious. Bruce didn't have much time to be relieved. Steve was stirring feebly and the monster spotted the movement and charged-

"_No!"_ Natasha cried. Bruce heard several popping noises and realized she was firing her pistol to draw the Hulk's attention away from their fallen comrades. There was an uncharacteristic note of panic in her voice as the monster turned towards her. _"I could use some help here, Bruce!"_

"I'm coming!" he told her. "Give me back control," Bruce directed at JARVIS, keeping one eye on the Hulk and the other eye on the propulsion system power readings. The AI released him and he tumbled for several meters downward. Miraculously he managed to get the correct balance in time and leveled off before he hit the ground. Natasha was sprinting towards him, away from the Hulk.

He cut the repulsors to drop into a horizontal position and twitched his thrusters, swooping between the Hulk and Natasha. The monster instantly went for the shiny, fast-moving object and turned away from Natasha. Somehow Bruce managed to right himself in the air. He bobbed and dodged ahead of the Hulk, firing repulsor blasts wildly to keep the monster at bay.

With Clint incapacitated, they had a serious problem on their hands. Bruce doubted Steve knew how to use a bow, and Bruce himself was just about as helpful in that regard. He kicked himself mentally for forbidding Tony from installing anything that could fire tranq rounds in the suit. That left Natasha as their best chance for bringing the Hulk down.

"Natasha?" he called over the comm. He ducked a green fist and flew backwards out of the Hulk's reach. "Can you take the shot?"

Bruce spared a glance in her direction and blinked to enlarge the image. Apparently the assassin had followed the same line of reasoning. She had slipped over to where Clint and Steve were lying on the ground, and had already coaxed an arrow from the malfunctioning quiver. Now she was wrestling the bow from where it was tangled around Clint's limp arm and one of Steve's legs.

"_I think so, but I'm no Hawkeye. I can barely draw this thing," _she voice was shaky but determined. _ "I'm going to have to get close."_

"I'll keep him busy," Bruce promised. "You can do this, Natasha."

He swooped around behind the monster and hovered near the ground twenty meters or so from the Hulk. "Hey, big guy! Over here!" he shouted, firing a repulsor blast past the Hulk's ear. "JARVIS, I want you to blast us off with full power if he gets within three meters, okay?"

"_Acknowledged, sir._"

The monster turned, exposing his broad back to Natasha. Bruce could see Natasha running into position over the Hulk's shoulder. The monster seemed to hesitate for a moment as if he sensed something was wrong. Bruce fired another repulsor blast, this time hitting the Hulk mid-chest. The monster was unable to ignore this direct challenge. He roared and charged at the armored scientist. Bruce stood his ground. Natasha tensed and loosed the arrow.

It wasn't the cleanest shot, but she managed to hit the Hulk between his shoulder blades. He roared once, twice, before swaying on his feet. He roared half-heartedly again and hit the ground with his fists out of frustration. The monster staggered and fell forward. He twitched for a few moments while massive dose of sedatives took hold. Finally, he lay still. Bruce knew from experience that it wouldn't be long now until the transformation began.

Bruce landed with a metallic _clunk_ near Clint and Steve. He misjudged the distance slightly and cut the thrusters too soon, so he hit the ground with a jolt and tipped over backwards. Steve had somehow dragged himself into a sitting position and was propping Clint upright. The soldier looked shaken and somewhat guilty. He held his shield arm awkwardly, as if it pained him, but he was too stubborn to say anything about it. He had his sleeve pressed to the gash on Clint's forehead. The archer's face was pale and streaked with blood. He was still unconscious.

Natasha joined them. Her expression was unreadable but her knuckles were white where they gripped Clint's bow. Her eyes kept flicking warily towards the shrinking Hulk.

Bruce retracted the faceplate, which whined loudly. He probably shouldn't do that again until Tony could fix it properly. "Trust me, he'll be out for a while," he told her with a slight smile. "Nice shot."

"Thanks," she replied automatically. Her expression didn't change; despite how completely ridiculous Bruce thought he must look in his awkward seat on the grass. She crouched down beside Steve and Clint to get a look at her partner. "We should get back to the tower. Barton needs a medic. Looks like you do too, Captain Rogers."

Bruce hid a frown. Natasha only called him Captain Rogers when she was angry with him. "No argument from me," Steve said, with a pained smile that was more of a grimace. His eyes were guilty. "Let's get out of here."

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_TBC... Please review! :)_


	4. Chapter 4

_A/N: You guys are awesome! Thank you to everyone who reviewed (especially you anons, since I can't PM you!), followed, and favorited since the last update. __Also, all the thanks to my most excellent beta Red Tigress! ____On to the chapter!_  


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**Entangled States**

Chapter 4

Clint Barton managed to escape medical in near-record time. He had a fresh row of stitches near his hairline and what was probably going to become the mother of all headaches in a couple hours once the painkillers wore off. He was under strict orders not to get his stitches wet, drink, or sleep for the next several hours. Of course, in that moment all the archer really wanted to do was shower, have a drink, and hit the sack. Clint sighed. That wasn't going to happen.

Instead of heading upstairs to Nat's for fresh clothes and some well-deserved rest, Clint headed down to the tower basement to find his teammates. Unfortunately he was needed to help deal with the current crisis: Tony and the Hulk. The archer tried not to make a face. It tugged on his stitches.

The fact that they had Stark down in the Hulk-resistant room meant tensions were running high. Nobody had used the room in months; everyone trusted Bruce enough these days to let him recover in his own bed on the rare occasion he got tranq'd. Clint paused to peer through the ultra-thick acrylic window as he passed. A blanket-wrapped Banner (no, that was _Stark_, he corrected himself) was lying on a cot inside the chamber. He looked like he was still out cold.

The remaining Avengers were already gathered in the little observation chamber outside the Hulk-resistant room. Clint sized them up from outside. Banner (still in Stark's body) had been extracted from the Iron Man armor. Natasha was still in her mission kit, and Steve was decidedly less spangly now that he was stripped down to his blue undershirt. His shield arm was in a sling. They looked like they had Banner cornered. Bruce worked Stark's fingers together nervously; a sign he was on the defensive. Clint sighed again. He didn't feel much like being caught in the middle of this fight.

"We can't keep him there. That chamber wasn't designed to be occupied indefinitely," Bruce was saying as Clint sidled into the room. Bruce shot him a pleading look over Natasha's shoulder, but Clint wanted to get a better sense for the situation before he started taking sides. "Besides, I'm going to need his help."

"It's not safe to have him running around in this state," Natasha retorted. She acknowledged Barton with a glance before spitting Banner with a green stare.

"I agree," Rogers said. He sounded about as tired as Clint felt, and a lot more worried. He flexed the fingers of his injured arm experimentally as he spoke. The archer wasn't particularly sympathetic; it was Rogers' fault he was concussed and therefore grounded for the near future.

Bruce managed to hide his grimace. It was funny how if Clint looked closely, he could see Banner's familiar expressions peeking through Stark's features. "Tony _can_ do this-"

"Banner, you know better than most that he can barely control himself," Rogers interrupted wearily.

"Drinking is one thing," Bruce shot back. His fingers stopped their nervous fiddling long enough to press around the arc reactor in his chest. There was an unconscious quality about the motion that made Clint wonder if he was aware he was doing it. "The Hulk is another. Tony knows that."

"We're in the middle of _Manhattan_, for God's sake! Can we take that chance?"

"We should at least keep him sedated until we know exactly what we're dealing with, Bruce," Natasha said. "Maybe until we can get you switched back."

"Even if I thought it was a good idea, Natasha, I'm not sure we can," Bruce told her, and Clint knew he was forcing himself to keep his voice even. "It's difficult from a practical standpoint. Nothing keeps my body down for long. That quantity of drugs over a prolonged period of time wouldn't be good for…well, _me_."

"I still think we need to bring SHIELD in on this," Steve started. "They're better equipped to handle-"

"Why? So they can knock him out and keep him in a cage?" the scientist snapped. "Because they will. God only knows what they'd do with him after that."

Steve sighed and ran a hand awkwardly through his hair. "You know that's not what I meant."

"I think that's exactly what you meant, Steve," Bruce retorted. His bright eyes had hardened. Rogers looked away, his cheeks coloring slightly. "I know that's what Natasha wants. Tony's not leaving my sight."

Natasha made a frustrated noise. "You saw how he was, Bruce. He was totally out of control! He'll be safer, we'll all be safer, if he's kept in a controlled setting."

"He was not _totally_ out of control," Bruce said sharply, and Clint could tell he was really struggling to keep his temper in check. Few things set Banner off like the idea of a cage did. "Look, Tony lost control because he didn't know what to expect from the Hulk." He pinched the bridge of his nose. "He actually got very close. It's just…it's hard to know how to resist him when you don't have a sense for what you're resisting."

Clint frowned, ignoring the twinge of pain from his stitches. He wasn't real keen to pick sides, but it seemed inevitable. He was walking a very fine line here between Banner and Nat. "So you think Tony'll be able to keep from hulking out because he knows what to expect now?"

Bruce's relieved look almost made up for Natasha's glower. "Yeah. Exactly, Clint."

Rogers looked dubious. "It's a heck of a risk, Bruce."

Bruce ran a hand through Stark's short hair. "I won't deny it's risky. But I don't know how we're going to switch back otherwise. At some point, we're going to have to build something, and that's Tony's department. I'm no engineer. I can work it out in theory, but we'll need Tony to develop the actual implementation."

"SHIELD has resources; what about-"

Bruce pinched the bridge of his nose again, and it suddenly occurred to Clint how _weird_ it was to see Stark making such a quintessentially _Banner_ gesture. "Steve, if this works, we will develop technology that will allow the transfer of one person's consciousness into the body of another. Do you really think SHIELD should have access to that?"

Rogers froze. Natasha scowled. Clint kept his own features carefully neutral. The crack on his employer aside, he was impressed with the scientist. Banner sure knew how to play Rogers. The soldier more or less worked for SHIELD now, but he still had a lingering distrust of the organization due to the Phase II debacle. It was one of the reasons Fury kept him around. Captain America kept everyone honest.

"You're sure you can't do this without Stark?" Steve asked. His resolve was cracking. Natasha shot him a _look_, but he ignored her.

Bruce glanced around at them uncertainly. "There aren't a lot of people on the planet I, uh…trust with my brain, Steve. Tony Stark happens to be one of them."

Natasha raised her eyebrows incredulously. Clint hid a laugh. She had a point.

"Okay," Steve said. "I won't go to Fury."

"Rogers!" Natasha exclaimed, sounding betrayed.

Steve held up a hand. "I'm not finished," he told her. He looked back at Banner. "I won't go to Fury. Not so long as you keep Stark in line." He glanced at Natasha. "We have to get them switched back, Romanoff. The sooner, the better. If Banner needs Stark to do it, he needs Stark. I don't see a problem so long as Stark's not hulking out." He stabbed his index finger at the scientist in Stark's body. "But, Bruce, one _hint_ of trouble, and I'm going straight to Fury."

Banner swallowed hard. "Fair enough."

"And what are we supposed to do in the mean time?" Natasha demanded, gesturing at Steve. "Pretend like everything's normal?"

Bruce looked sheepish. Clint smirked. He was willing to bet the scientist hadn't quite thought that far ahead. "Uh, more or less."

"This is _insane_," she muttered under her breath.

Clint spoke up. "I'll help keep an eye on Stark. Worst comes to worst, we can always knock him out again."

His partner looked slightly mollified by his words, but Clint knew she wasn't happy that he'd sided with Banner and not her. Whatever, it wouldn't be the first time they'd disagreed. After a tense moment or two, Natasha folded her arms across her chest. She recognized she was outnumbered and backed down. Clint knew it was as close to consent as they were going to get from her.

"C'mon, Rogers," Natasha said in a neutral voice. "We need to report in before Hill gets suspicious."

She pressed the button to open the door and gestured the soldier through it. Once his back was turned, she shot Clint a _look_. He rolled his eyes skyward and obediently followed her, making sure the door shut behind him. Banner didn't need to hear him getting chewed out.

"_Really_, Clint?" she whispered furiously, as soon as Rogers was out of earshot.

Clint gave her back her glare. "I'm not doing this for Stark, Nat."

"He's dangerous!" Natasha hissed.

"Stark's a pain in the ass but he's always come through when the chips are down," Clint countered in a low voice. "Banner trusts him. He's not stupid, Tash; if he thought Stark couldn't hack it he'd tell us. Just try and keep Hill off our backs until he can figure something out."

Natasha sighed. "Fine. Just…be careful, okay?"

Clint grinned lopsidedly at her. "When am I not?"

The assassin rolled her eyes and swept down the hall after Rogers. Clint chuckled and reentered the observation chamber. Bruce was now slumped in a chair at the narrow table up against the window into the Hulk-resistant room. He looked somewhat overwhelmed. It was a far cry from the giddy excitement he'd shown after the flight home. Clint guessed the gravity of the situation was beginning to sink in.

"Thanks," Bruce told him quietly. "I know Tony won't make this easy."

Clint shrugged. "I thought that went pretty…well," he said. He eyed the table and decided it probably wouldn't take his weight. Instead, he grabbed another chair and dragged it around so he could straddle it cowboy-fashion.

Bruce sighed and looked down at his unfamiliar hands. "I didn't think Steve would cave so easily."

"Nat's not happy."

"You think she'll go around Steve?" Bruce asked, a hint of worry in his tone.

Clint thought for a moment. He'd volunteered to help deal with Stark because he knew Natasha would be more open to the idea if someone she trusted unhesitatingly was involved. "Not without a good reason," he replied. "If Stark does something stupid, she won't hesitate."

"I suppose she won't," Bruce said glumly. He winced suddenly and clutched at the arc reactor in his chest.

"You okay, man?" Clint asked.

Bruce started to take a deep breath, but he stopped short and grimaced. His fingers massaged the area around the arc reactor. "Yeah. The arc just…takes a little getting used to." He glanced up at Clint and smiled a little ruefully. "I should be asking you that question. How's the head?"

Clint hid a smirk. It was classic Banner avoidance by changing the subject. Well, fine, he'd humor the scientist for now. "Been worse."

Bruce paused. "You…went down pretty hard."

The trace of concern in his tone made Clint smile slightly. Bruce was accustomed to seeing the aftermath of their injuries in medical, rather than as they happened. "That shield is _hard_, man," he said lightly. "Don't get why Rogers can't use something a little more…conventional."

The corner of Bruce's mouth quirked upward. The little motion was almost lost in Stark's goatee. Clint was not unaware of the irony of his statement and he smirked. But the moment of levity faded quickly. Bruce leaned forward onto his elbows to cradle his face in his hands.

"You have no idea what you're going to do yet, do you?" Clint observed.

"I don't even know what happened yet," Bruce admitted through his fingers. "JARVIS is processing the data recorded by the suit from the blast, and I took EEGs of both of us while you were in medical."

He looked up and reached over to tap on the surface of the room's single computer monitor. Several sets of squiggly lines flashed onto the display. Clint recognized them after a moment. Right, brain waves. After Loki, he'd been scanned by SHIELD several times. He shot Bruce a questioning look.

"This one's me after the accident," Bruce said, pointing at a set of lines. He gestured to the next one down. "This one here is Tony. See this cluster right here? That's the Hulk. If you put my readings from before the accident up, you can see the Hulk blip. It's not there now."

"What's that tell us?"

"Well, it proves that something actually happened to us; it's not just a psychological effect. It also shows that the Other Guy is in there with Tony, and that I'm Hulk-free," Bruce told him. He looked a little sad. "I never thought I'd be saying that," he added softly.

They both glanced through the thick window into the chamber. Bruce had JARVIS projecting Stark's vitals onto the acrylic. They were all stable, slow, and even. He was still safely asleep.

"How much longer you think he'll be out?" Clint asked. He glanced at his watch and resisted the urge to grimace. It was early now, rather than late.

"I'd say at least a few more hours. Hopefully the rest of the night. After two transformations and the tranq…he's not going to be happy when he wakes up."

"It's not Stark that worries me," Clint said.

The physicist rubbed at the arc reactor again absently. The pale blue light glowing through Stark's shirt made him look tired. "The Other Guy, the Hulk, should be pretty quiet for the first twenty-four hours. Maybe forty-eight if we're lucky. As long as Tony doesn't completely panic when he wakes up, I think we'll be okay." He glanced at the archer. "Much as I hate the idea of locking him up, I won't let him out of there until I'm sure he's stable."

"I know," Clint said. He grinned, despite the fact that it hurt his stitches, and stood to leave. Orders be damned; if he was going to be stuck down here on Hulk-watch duty, he wanted a shower first. "I'll remind Natasha. Gimme a shout if you want to catch a nap. I've gotta stay up all night anyway."

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_To be continued... Please review/ask stuff/comment! You guys have some great insights! :)  
_


	5. Chapter 5

_A/N: Hello readers! Thank you to everyone (you too, anons) who reviewed, favorited, and followed. Huge thanks to Red Tigress of the Beta Branch for her edits and extensive Stark expertise! The next chapter might be a little delayed because I'm going to be traveling for the holidays, just so you all know. :)_

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**Entangled States**

Chapter 5

The first thing Tony became aware of was darkness.

He felt his eyes move under their lids. He could sense it was darker than usual. He was so accustomed to a certain level of ambient light that it was strange for it so suddenly be so dark.

Tony shifted slightly. A rough blanket rasped across his bare skin. He moved again, and dull stabs of pain raced through his body. His lips pulled back into a wince. God, he _ached_. Deep somewhere inside his mind _something_ stirred. He tried to ignore it. It would be far better to just go back to sleep.

But the ache in his limbs and the growing throb in his head proved too much for him to sink back into oblivion. Tony dragged his eyes open. It _was_ dark. He blinked several times, trying to focus in the unnatural darkness. There was something missing. He stared up at the obscured ceiling, trying to figure it out. It was never dark around Tony. Not since he'd installed the arc and became a walking flashlight-

His head snapped up. The arc. Where was the arc reactor? Tony's hands flew to his chest. His fingers scrabbled against flesh and the rough material of the blanket. The choke of fear began to spread into his throat. The arc was _gone_. The arc was _gone_, and so was the hole over his heart-

"_Tony!"_ a very familiar voice called. Despite his growing panic he noticed a mechanical timbre about the sound; it was an intercom. Where the hell was he? _"Tony! It's Bruce. It's okay. You're fine. Try to calm down."_

_The hell?_ Tony thought. That was not Bruce's voice. His breath was coming fast and shallow now; his heart beginning to pound with the rush of adrenaline. The lights came up, and the pain as they lanced into his eyes was somewhat welcome because he could see his surroundings. He was on a cot in some sort of a concrete room. A thick window was to one side. A cell. He was in some kind of cell.

He cried out in shock and pain as the _thing_ in the back of his mind surged forward at the realization. It was huge, crushing, suffocating Tony in his own head. His body curled in on itself. He clutched at his throbbing head. Instinctively he squeezed his eyes shut to keep the _thing_ from escaping. "What's happening?" he tried to say, but the words caught in his dry throat and came out as a choked noise.

"_Tony!"_ The voice claiming to be Bruce said sharply. _"It's me, Bruce. We switched places, remember?"_

Shards of memory pierced through his fear. Catching the grenade. The blast. Waking up afterwards, confused and naked. Looking up at himself, at Bruce, in the armor. The invasive presence of the monster in his mind. But it wasn't just a creature, he suddenly realized. He was in Banner's body. It was the _Hulk_.

"_It's not working! Clint, you have to let me in there-" _Tony finally recognized the frantic voice. It was his own. But the words belonged to someone else.

"_What are you nuts? He could kill you!"_

"_Tony, you need to calm down or he's going to come out again!"_

No. That was _not_ going to happen. He wouldn't let it happen. Tony gritted his teeth. He tried to focus on taking slow, even breaths, like he'd seen Bruce do a hundred times. The monster did not go quietly. He faded from the front of Tony's mind, bleeding away with the remnants of his adrenaline rush. "I'm okay," the inventor finally managed to choke. He was panting with exertion. "What happened?"

He heard the sound of heavy bolts retracting and the soft _woosh _of the door, followed by soft footsteps. A warm hand pressed his shoulder. Tony forced his eyes opened and looked up into his own face. He couldn't help pulling away a little with shock even as Bruce gave him a relieved smile.

"You…went green," the physicist told him. He must have looked particularly unnerved, because Bruce added hastily: "Everyone's okay-"

Tony had a sudden impression of rage and of swinging a huge fist at a shiny round target. A puny human flew backwards. Laughter boomed in his head. "Did I-did I deck Rogers?" he interrupted. He cursed himself mentally for stuttering.

Bruce smiled slightly. "I thought you might remember that. The Hulk was going for Clint. Steve tried to distract him and got a little too close."

Tony waved off Bruce's hand and hauled himself into a sitting position. He took a sharp breath through his teeth as the room spun, but he clung gamely to the edges of the cot until the spell passed. The cool air raised goosebumps on his bare skin.

"Been wanting to take a swing at him for months," he quipped lamely. Tony couldn't help feeling a small pang of guilt; his personal feelings about Rogers aside. He ran his hands through Banner's mass of curly hair, mostly to hide the mixture of emotions on his face. Jesus_ Christ_. He was the Hulk.

Bruce studied him for a moment. He could feel the scientist's eyes boring into him. "Steve's fine, by the way," Banner told him. "He tore some ligaments but he'll heal up by the end of the week. Clint's okay too."

Damn him for being so perceptive. Tony had an image to maintain. He tried to rearrange his unfamiliar face into a neutral expression. The bit about Barton threw him, though. If he'd hurt the archer, too, Tony didn't remember it. It was all a green- tinged haze. "What happened to Barton?" he asked, forcing himself to look up. At least his voice was steadier now.

Bruce glanced at someone over Tony's head, and the inventor followed his gaze. Barton gave him a mock salute through the thick acrylic window. Tony finally realized where they were. They were in the Hulk-proofed room in the basement of his tower. He felt like an idiot for not noticing that earlier. What a stupid thing to panic about. There was a rumble of dissent from the back of his mind. Cages were always something to panic about. Tony tried to brush the alien thought away, disconcerted.

Banner cringed a little. "You, uh, threw Steve into him," he said. He immediately tried to reassure Tony again. "Like I said, he's fine. Right, Clint?"

"_Yeah, 'cept for the fact my head feels like it's gonna explode," _Clint drawled over the intercom. _"Thanks for that, shellhead."_

Bless Barton for giving him snark and not sympathy. "Yeah, well you gave as good as you got, hawkass," Tony retorted with another wince. His head was pounding abominably, and his vision still had a fuzzy quality about it. Leftovers from the tranq, Tony guessed. He'd certainly seen Banner dealing with the side effects more than once. Either that, or Banner's eyes really did suck.

"How are you feeling?" the scientist asked. His face, Tony's face, was creased slightly with worry. Looking at him was like gazing into some twisted mirror. It was Tony's face, but the expressions were just…wrong. Tony couldn't look at him for long without feeling a little panicky. To his private shame, Bruce didn't seem nonplussed at all to be looking into his own face.

"Fine," Tony lied. His head felt like it was going to split and his whole body hurt and he was trembling weakly like he'd just recovered from a nasty bout with the flu or something. His stomach grumbled, and Tony suddenly realized he was famished. There was a faint rumble of approval from the back of his mind at the thought of food. _Knock it off_, he directed at the monster. Without really knowing why he was doing it, Tony visualized a heavy door and pictured it slamming shut on a set of green fingers. The foreign thoughts abruptly contracted into a greenish ball on the edge of his consciousness.

Bruce clearly wasn't falling for it. He handed Tony a bottle of water. "It's going to be pretty lousy for a day or two," he told the billionaire as Tony cracked open the bottle and gulped the water greedily. "Careful. Take it slow, okay?"

He only half listened while Bruce lectured about triggers and keeping the Hulk under control and things he had to avoid. Tony was more interested in the pile of his clothing Banner had brought with him. The familiar scent of the fabric helped ground him, even if everything felt different in his new skin. Dressing was painful and it took some effort to tug his shirt over his head. The material puckered a little in the center of his chest where the arc reactor usually stretched the fabric. He rubbed the place absently. It was weird to feel skin there and not metal. Hell, it was weird to have _feeling_ there again.

On some level, he _was_ listening to Bruce and making the appropriate replies, but he couldn't help fixating on the strange alien presence in his mind. It was always there, a great green mass lurking on the fringes of his consciousness. He couldn't help probing, prodding at it a little. It was like going to the dentist…they always warned you not to mess with whatever got novocained, but it was impossible to resist. It just felt so weird.

And this _thing_ poked back.

After he withstood an unexpected jab to the ribs without hulking out, Banner deemed him ready and Barton relented, releasing them both from the Hulk cell. Clint disappeared into the tower, leaving Tony and Bruce to their own devices. Despite Banner's insistence that he get some rest, Tony wobbled towards the workshop. The last thing he wanted to do was be alone in the dark with the Hulk lurking in the back of his mind. Better to distract himself; fill his mind to the point he didn't notice the intrusion of his consciousness. And where better to be distracted than the workshop? Besides, it wasn't like he was doing anything hardcore. He could relax on that old couch he kept in there for when he worked late and he and Bruce could talk solutions to their…problem.

It took Tony two tries to key in his code to the workshop with his unfamiliar fingers. It was a bit like wearing a new pair of gloves, he decided. Bruce followed him inside. Tony headed towards the couch, but he suddenly remembered he had leftover pizza in the refrigerator. Excellent! He went for it. He crammed the first slice into his mouth and damned if it wasn't the most delicious thing he'd ever eaten in his life, even better than that cheeseburger after Afghanistan-

"I really don't think that's a good idea, Tony," Bruce told him, making a face. "You should start with toast or something and work your way up."

Trust Bruce Banner to rain on his parade. "_Your _body just burned about eighty bazillion calories hulking out and I'm _starving_," Tony retorted around a mouthful of food. He was going to actually collapse in the next thirty seconds if he didn't get something more substantial in his stomach than freaking _toast_. He selected another slice of pizza and started on it with relish. "This is the best idea I've-"

He managed about half of the second slice before there was an ominous rumble from his stomach. Tony stopped. He suddenly felt queasy. Oh no. He hated it when Banner was right. Bruce merely shook his head as Tony bolted for the bathroom, clutching his stomach. He made it just in time.

The engineer retched for several minutes. Banner settled down at a nearby monitor as if nothing was wrong and began bringing up files, so he could pretend to be working even while he kept an eye on his friend. Embarrassed and miserable as he was, Tony was glad for the company. He winced as his insides knotted further. God, it was like the hangover from hell. He was absolutely famished and completely unable to keep anything down. He didn't even dare to move from the bathroom floor.

"This sucks," Tony gasped at Bruce between spells. Worshiping at the altar of the porcelain god was _not_ how he wanted to spend his day. "Hulkovers suck. Worse than real hangovers."

Bruce glanced up from his monitor and chuckled sympathetically. "Tell me about it."

The engineer held up a finger at a rumble from his stomach. He winced. "I am never giving you crap about you being lame after this ever again. I also take back all previously given crap."

"Can I get that in writing?" Bruce replied with a grin.

Tony glowered at him, but only for a moment as his stomach rebelled and he retched. "This happens every time you go green?" he groaned when the spell had passed. He slumped against the wall, feeling thoroughly pathetic.

"No," Bruce explained. "It's worse when I transform more than once in a short period of time. Or if I get tranq'ed too soon. Or in your case, both."

"Lucky me," Tony complained. He wiped his mouth on the back of his hand. "Seriously, I have not felt this bad since, like, last Tuesday."

The scientist chuckled again and went back to his monitor. "I warned you to take it slow."

"C'mon, Banner, give me something. Anything. I don't care what it is: bad porn, pictures of cats with misspelled captions, _anything_," Tony begged. His insides twisted painfully, despite the fact that there was nothing left to twist. His unfamiliar fingers clenched on cool ceramic. Like a hangover, he didn't have anyone to blame but himself for his misery. It wasn't a comforting thought. "I need a distraction from this Hulk-induced agony."

"How about some of the data from the suit?" Bruce suggested. He fiddled with some of the computer controls. The holographic projectors closest to Tony flared to life in shades of blue and green. Bruce reached out and spun the display so they faced the engineer. "Before and after EEGs. Me, you, and that's the Hulk."

Tony squinted at the squiggly lines, although Banner's eyes were better at distance than they were at reading. He made a mental note to ask Bruce for his glasses. "Any insights into what happened yet?" he asked.

Bruce shrugged. "Whatever it is, I doubt this is what the weapon was intended to do. It was essentially an electrical surge. If that's the case, I guess it's not completely unreasonable we switched places. Neuron activity is essentially electrical, right?"

"Suit usually acts like a faraday cage; I shouldn't have been zapped at all. Maybe one of the gloves was compromised," Tony observed. He eyed Banner critically. He was dressed in one of the faded shirts Tony had been trying to convince him to get rid of and his slightly threadbare trousers. He raised his eyebrows disapprovingly at the physicist and Bruce gave him an exasperated sigh.

"What?"

"You dress like a professor," Tony told him. He glanced back at the holographic display. If he looked at Bruce out of the corner of his eye, and tried to ignore how the physicist was speaking with _his_ voice, he could pretend it was just Banner and not Banner _wearing his body_.

"I _am_ a professor," Bruce said sourly. "Well, I was." He prodded the controls again and a different set of waves appeared on the plots. "Look, I had JARVIS parse all the readings out by millisecond, so we can see how current and potential changed over the course of the explosion-"

Tony let out a low whistle at the complexity of the plotted data. "Yikes. That's going to be fun to recreate. Unless we captured one of those grenades," he mused. "You're dressing _me_ like a professor," he added.

Bruce pinched the bridge of his nose. "Tony, we have bigger problems than your vanity right now."

"You're the one who made such a big deal about SHIELD not knowing something's up," Tony retorted, not bothered in the least by Banner's accusation of vanity. "If you'd just-"

"I'm not wearing any more of your clothes, Tony." Bruce said flatly. "Be serious for a minute," he continued, an undercurrent of worry in his tone. "Do you really think recreating the accident is the best course of action?"

Tony wasn't any more thrilled about the prospect of getting electrocuted again than Banner. "You got a better idea?"

The physicist thought for a moment. "No," he admitted with a resigned sigh.

"Exactly," Tony said. He cocked his head to one side, studying Bruce again. "SHIELD aside, I think Pepper's going notice the difference when she gets home," he added nonchalantly.

That got Banner's attention. The scientist looked up with obvious alarm. "Pepper?" he demanded. "What do you mean, _Pepper_?"

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_To be continued. Please review! :)_


	6. Chapter 6

_A/N: Egads! Apologies for the long delay for this chapter, everyone. Let's just say it was a...rough "vacation". I'll try to stay closer to schedule now! As usual, thank you to everyone who reviewed and favorited, and welcome to all the new followers! Thanks also to Red Tigress and the lovely members of The Beta Branch for beta reading and helpful comments!  
_

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**Entangled States**

Chapter 6

Clint Barton ran a hand through his hair and chuckled ruefully. He was perched on the bar in Stark's hypermodern concrete-and-glass penthouse, waiting for Pepper Potts to arrive home. The archer glanced at his watch. He had twenty minutes or so to figure out how the hell he was going to tell her that her boyfriend had just switched bodies with the Hulk. Rogers was better at this sort of thing; delivering the bad news or whatever. Too bad he'd ditched the tower to deal with SHIELD. Clint stretched and reached over to pour himself another slug of Stark's scotch. Normally he didn't go in much for scotch, but Stark always got the good stuff and he sure as hell owed Clint a drink or two for making him deal with all this shit.

He swirled his glass. Stark had wanted to see how long he and Bruce could keep up the charade of being each other before Pepper noticed. It was no skin off Clint's nose if Stark wanted to get himself sentenced to sleeping on the couch for the next six months, but Banner had seemed upset by the idea and Clint had intervened to prevent a full-on argument between the two geeks. Realistically there was no way they were going to get through this mess without filling Pepper in about the situation, and the agent was the logical choice. He'd left Bruce to keep Tony in the workshop until Clint gave them the all clear. He took a sip of his scotch and chuckled again. Somewhere (probably the Hulk-free environs of the helicarrier) Natasha was laughing at his well-intentioned misfortune.

At this point, he should have known things wouldn't go according to plan. The elevator dinged ahead of schedule. Clint jumped. He dropped off the bar, cursing under his breath as the sudden motion caused the stitches on his forehead to tug painfully. Pepper Potts strode through the double door with the _click-clack_ of stiletto heels and a whiff of Chanel. She dragged a small designer suitcase behind her.

"I'm home!" she called. "Tony?"

Pepper stopped in her tracks when she saw Clint. Her eyes widened as they took in the row of stitches on Clint's forehead, the dark circles under his eyes, and the drink in his hand. She released the handle of her bag. It fell to the tiled floor with a clatter. "Oh," she said softly. "Oh God. What happened, Clint?"

Christ, she thought he was here because something had happened to Stark. Clint cursed himself for not realizing what this looked like sooner. Before he could reassure Pepper, however, he was interrupted by the chime of the elevator. Damn it. It could only be Stark. Apparently Banner hadn't been able to keep him in the workshop after all.

Sure enough, what appeared to be Bruce Banner swaggered through the elevator door. Of course, it wasn't Bruce, but Pepper didn't know that. Clint swore again mentally. So much for their plan.

"No, wait!" Tony Stark's voice called after him, but Clint knew it was actually Bruce. He lunged after Stark, but the damage was already done.

"Tony!" Pepper cried as soon as Banner came into view. He froze. She darted to him and immediately pulled him into an embrace. Clint smothered a guffaw as the scientist's face colored around Stark's goatee and he tried and failed to dodge her kiss. "Are you all right?"

"Uh, didn't Clint explain?" Banner asked hesitantly, wriggling out of her grasp and looking desperately at Clint. The agent shrugged.

"Explain what?" Pepper asked.

"What do they pay you for at SHIELD, Barton?" Stark piped up and Clint retaliated with his best Agent Barton glare. Pepper's eyes narrowed slightly. It wasn't something Banner would say. She looked between Banner and Stark, clearly puzzled by what she observed.

The differences were particularly striking when Stark and Banner were together, Clint thought, and it wasn't just because they appeared to be wearing each other's clothes. Banner's (actually Stark's) movements were larger, more confident and open. His speech pattern was just…off, and a slight sarcastic edge had crept into his voice. Bruce in Stark's body was even more surprising. Between his slightly sheepish expression and the awkward slump of his shoulders, he barely resembled Tony Stark. He seemed to hunch inward, like Bruce did when he was feeling uncomfortable. Or whenever he was out of the lab.

"What?" Pepper breathed. She looked between Banner's guilty face and Stark's amused expression. Her eyes settled on Tony with uncanny accuracy in spite of his exchanged body. "What did you do?" she snapped, anger bleeding into her voice. "_What did you do?_"

"How is this _my_ fault?" Tony protested. Pepper put her free hand on her hip and glared.

"Um," started Bruce. Pepper looked up at him and he anxiously ran a thumb over the knuckles of the opposite hand. "It's a bit-"

"_Freaky Friday_," Tony interrupted matter-of-factly, his confidence recovered after a moment out of the spotlight of Pepper's wrath.

"It's Tuesday," Pepper said, sounding confused. Her fingers tightened on Bruce's arm and she glanced up at him. "Tony, what's going on?"

"What Tony's trying to say," Bruce started, raising Stark's bright eyes sheepishly, "is that we've, uh… switched bodies."

She paused for a beat while Banner's words sunk in. "_What?_"

"Um, I'm Bruce," the physicist occupying Stark's body said, tapping the arc reactor in his chest. "And that's Tony."

Pepper blinked several times. She leaned forward to peer closely into his bright brown eyes. Bruce pulled instinctively backwards, like he always did when someone got too close. She released her grasp on Bruce's arm and moved over to Tony. She studied Banner's face closely. "Tony?"

Bruce's features twisted into Stark's trademark rakish grin. He looked too damn smug for someone who hadn't been able to keep solid food down all day, Clint thought. "Hey, babe."

Pepper's eyes widened. "Oh my _God_," she exclaimed, and sank into the nearest chair. Clint could sympathize; it was weird as hell seeing Stark's expressions on Banner's face. She squeezed her temples wearily. "I need a martini. You are going to make me a martini. Very dry. With olives. Lots of olives," Pepper ordered, unable to tear her eyes away from Tony in Bruce's body. "At least three olives."

Tony smirked. "But it's not five-"

"_Tony!_"

He threw up his hands in mock defeat and sauntered behind the bar. Pepper stared, because he was Bruce Banner and Bruce Banner didn't _saunter_. She took a deep breath and visibly pulled herself together. "Then you are going to explain how this happened," she added. She flicked her eyes between Bruce and Tony. "More importantly, you are going to explain how you are going to fix it."

Clint couldn't help grinning, despite the tug on his stitches. Bruce shuffled over and dropped onto the semi- circular couch opposite Pepper. "I'm sorry, Pepper," he apologized. "We thought it was, uh, too much for just a phone call. Clint was supposed to break it to you slowly, but Tony…had other ideas."

"Slow isn't really my style," Tony called from behind the bar, gesturing at him with the lid of the olive jar.

"No, you're all about giving your girlfriend a heart attack," Clint teased. Tony glowered at him, but Pepper managed a small smile and that was the only thing Clint really cared about. The archer grinned and dropped onto the couch beside Bruce. "Didn't mean to scare you," he told her. "It was a little hard to explain."

Tony joined them. He handed Pepper a martini glass with three olives rolling in the bottom. She accepted it wordlessly. He didn't take a seat, but remained standing just behind her chair. "Just tell me what happened," she said.

Bruce and Tony looked at each other, and Clint decided to let them deal with it. He'd filled Banner in on the details of the accident while they had been waiting for Stark to come around. "Uh, there's not much to tell," Bruce said.

"I only saved his life," Tony interjected proudly.

"He caught a grenade meant for me," Bruce explained, at Pepper's questioning glance. "It went off before he could throw it, and when we woke up…" he shrugged, "We were like this."

Pepper's features softened. "I see," she said evenly, but Clint caught a note of pride in her voice. She took a measured swallow of her drink. "How do you plan on switching back?"

Tony and Bruce looked at each other again. "Obviously, what, uh, happened isn't supposed to be possible," Bruce said. "So we're going to try to recreate it. If we can reproduce the phenomenon that switched us in the first place, we think it might reverse the process."

"Won't that be dangerous?" Pepper asked, and this time Clint could hear the effort it took her to keep her voice even. Tony reached down and placed a hand on her shoulder. She shied away at first from the touch (probably because it was Banner's hand and not Tony's), but she relaxed after a moment and let him leave it there. Bruce himself had Tony's eyes fixed on a spot on the carpet in front of Clint's left boot.

"Nothing Banner and I can't handle," Tony said confidently. Clint hoped it wouldn't turn out to be a lie. "We are the kings of not-possible."

Pepper didn't look particularly reassured, but she didn't press the issue.

"There's, uh, something else you need to know," Bruce continued, with a nervous glance at Tony. Stark nodded and he continued. "The Hulk…he didn't transfer with me."

The blood slowly drained from Pepper's face. "You mean…" she trailed off, looking up at Tony with horror. "You can…did you…?"

"Yeah," Tony replied casually, but Clint could tell it was forced. "I can. And I did."

She set down her glass and pressed her fingers to her eyes. "God." Tony squeezed her shoulder gently, and she reached up to take his hand. Out of the corner of his eye, Clint saw red spots burning on Banner's cheeks. He seemed fascinated by that same spot on the carpet again.

"Hey, it's okay," Tony told her, so softly it was almost an undertone. "It's not as bad as it looks."

Pepper looked up at him, real fear and a little disbelief all over her face. Her knuckles whitened on his hand. He stroked the back of her hand with his thumb. She took a deep, slightly shaky breath and let it out slowly. Her features smoothed. "Does SHIELD know?" she asked Clint.

Clint smiled. Pepper Potts was nothing if not practical. "No," he replied. "We're gonna try to keep it on the down low. So long as thing's stay quiet, there's no need for them to get involved."

Pepper understood better than most why neither Bruce nor Tony wanted SHIELD's input, and the agent trusted her to read between the lines and figure that SHIELD would get involved if things went south. "What does this mean for this evening, Tony?"

Bruce raised an eyebrow. "What about this evening?"

"There's a charity event tonight at the Met sponsored by Stark Industries," Pepper told them. "That's why I came back today. Didn't Tony tell you?"

Clint and Bruce both shot looks at Stark. He hadn't mentioned anything about a public event. Tony shrugged off their disapproval. "Can we all just take a minute to be impressed that I, _one_, remembered Pepper was coming home, and _two_, got the right day?"

Clint rolled his eyes. "You couldn't remember why, though," Bruce retorted. "You aren't going anywhere, Tony. You don't have the control to leave the tower yet. It's too risky."

Tony scowled, but he must've recognized the wisdom in Bruce's words because didn't say anything. "Think you're gonna have to cancel," Clint told him.

"No. We can't do anything that will attract attention to Tony," Pepper said thoughtfully. "SHIELD will start asking questions if we do. A lot of preparation went into this event, security, that sort of thing. We've been setting it up for months. Tony can't just back out now."

Clint raised an eyebrow. "Going somewhere swarming with paparazzi doesn't exactly scream low-profile to me."

"He's _Tony Stark_," she countered. "Much as I hate to say it, lying low would attract attention."

Clint had to concede the point.

"Actually," Tony piped up, stabbing a finger of his free hand towards Banner, "_He's_ Tony Stark."

Three pairs of eyes settled on the scientist. The conclusion was obvious. Bruce looked frantically between them. "No. Oh no. Oh no no no," he protested, plainly terrified by the thought of impersonating Stark. His borrowed fingers began to worry the band of Tony's Rolex. "I can't pretend to be you, Tony!"

Stark raised his eyebrows. "How hard can it be?" he said airily, but Clint could detect a note of bitterness through Banner's voice. "Put on a tux, ride in a fancy car, make an ass of yourself for the press…easy. I could do it in my sleep." He frowned for a moment. "Come to think of it, I probably have."

The corner of Bruce's mouth quirked reluctantly upward. Clint suspected that had been Tony's intent. He flashed a slightly painful grin at the anxious scientist.

"You can skip mugging for the photographers if you want," Pepper said kindly, ignoring Tony's brief splutter of disappointment. She had her Starkphone out, and Clint noticed she was scrolling through a calendar of some sort. She bit her lower lip while she read. "We should be able to reschedule everything else for the near future while you two work this out, and I can handle the board of directors. But this one event isn't optional. Tony has to make an appearance."

Bruce looked up at her, indecision plain on his face. She smiled at him. "I'll be with you the whole time, if you want."

The scientist glanced around. He forced his nervous fingers apart and set one hand on either thigh with an air of finality. "I've, uh, been wanting to go to the Met for a while," he said. "Okay. I'll do it."

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_Please review! :) I love hearing what you guys think!_


	7. Chapter 7

_A/N: Against all odds, a new chapter for you guys! Unfortunately the next one might be delayed due to a crunch period at work. I'll post something on my profile if it looks like it's going to be a big delay. Many thanks to all reviewers, readers, and people who favorited and followed! :) Also huge thanks to Red Tigress and Zarannya of The Beta Branch for beta reading!_

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**Entangled States**

Chapter 7

_Tony raised his eyebrows. "Breathing exercises?"_

"_Yes," Bruce told him. "Breathing exercises." His black bow tie hung loosely around his neck and was afraid to sit in case he wrinkled his coattails. He checked his watch. He was running late, but he didn't want to leave until he gave Tony some tools to deal with the Other Guy just in case something happened while he was gone. _

_Tony's reply dripped sarcasm. "Do I look like I'm in labor?" _

_Bruce was rapidly losing his patience. He was stressed as it was, and the engineer's flippant remarks were not helping. "Look, it works for me," he growled at Stark. He tugged at his shirt collar. "Do you have any idea what will happen if you transform-"_

"_Yeah I've got a pretty good idea," Stark interrupted with a little heat. He recovered his nonchalance and shrugged. "If it happens, it happens. Isn't that what Barton's here for? Quit worrying."_

"_Tony," Bruce pleaded. He pinched the bridge of his nose wearily, rubbing the place where his glasses usually sat. "Steve will go to SHIELD. If anything goes wrong, he'll go to SHIELD. Do you realize-"_

A warm hand suddenly closed over his own. Bruce jumped, startled out of his reverie by the unexpected touch. His fingers were gently detached from his shirt collar. "You're doing it again," Pepper told him. She smiled and guided his hand back down towards the leather seat, away from the collar he had unconsciously been tugging. "I know it fits; it's tailored."

"Sorry," Bruce apologized. He was seated stiffly beside her in the back of the Rolls-Royce, trying not to think about how the tuxedo he was wearing probably cost more than he'd made in a year as a graduate student. He looked up at her sheepishly. "I, uh, don't even remember the last time I wore one of these."

Pepper laughed. "I'm going to guess it wasn't for the Stark Industries' Benefit to Rebuild New York." She wore a deep green formal dress that brought out the red in her hair. Dangling round earrings set with diamonds in a pattern reminiscent of the arc reactor danced below her ears when she moved. "Just try to relax. You don't have to make a speech or anything."

Easier said than done, Bruce thought. He found Tony's MIT class ring and began to twist it around his finger. It fit surprisingly well. But it wasn't surprising, as it was Tony's ring and this was Tony's body. Tony's reflection stared back at him from the dark window. The glow of the arc reactor just barely shone through his white shirt, giving the image an ethereal hue. Bruce let his eyes fall shut and inhaled slowly. _Relax, Banner._

"_Oh please," Tony scoffed. "Relax, Banner. We can handle SHIELD."_

"_Tony-"_

"_It wouldn't be the first time we pissed off Fury. Besides, the Hulkbuster unit needs something to do-"_

_A cold hand clenched his heart at the word 'Hulkbuster'. "I'll have to leave New York!" Bruce shouted at him, his desperation to make Tony understand finally overcoming his self-control. "Can't you see? If you transform, if you smash up Midtown, I'm the one who'll have to leave!" The billionaire gaped at him, shocked into silence. Bruce never shouted. The scientist ran his hands through his hair, trying to get a grip on his temper. He continued in a quieter voice. "God, Tony, I don't want to leave. I don't want to run again. I'm so tired of running…"_

"Bruce," Pepper said. She took the hand that was nervously playing with Tony's ring and pulled it away. "Relax. Do you want to go over it again?"

The physicist opened his eyes, embarrassed to have been caught in his anxiety again. She was referring to the sequence of events that would occur once they arrived at the red carpet outside the Met. He ticked them off in his head. Get out of the car. Smile and wave. Walk firmly past the photographers. Don't stop; don't answer questions. Most importantly, _don't stop_.

"No, I think I've got it," he answered, looking back out the window. It wasn't far now. He swallowed hard. Bruce could feel Pepper's eyes on him. He ran his fingers over Tony's goatee and went for his collar again, but he managed to stop himself before he tugged on it. This was Tony's sort of thing. It should be Tony here now. Bruce should have been the one alone in the tower. He sighed. That was how it was, and how it was supposed to be.

"Bruce," Pepper said softly, and he forced himself to look at her. She smiled slightly. "Don't. It's not going to kill Tony to stay in for one night." He managed a chuckle despite his nerves, and her smile deepened. "I know this is a lot for you, but promise you'll at least _try_ to have a good time?"

He gave her a sheepish smile. "Okay." The Metropolitan Museum of Art loomed majestically outside their window, and the car came to a halt before he could say anything further. Bruce's stomach flipped. A long strip of red carpet led down the many steps. Either side was lined by barriers and several NYPD officers. The entire length of the carpet was swarming with reporters bearing cameras, and behind them, a large crowd of regular people. His mouth went dry. Not for the first time, Bruce wished he could take a proper deep breath. It was painful with the arc reactor, however, and he'd promised Tony he wouldn't let Pepper see.

Pepper squeezed his hand encouragingly. "Smile and wave," she reminded him. She handed him a pair of Tony's oddly tinted designer sunglasses. "And don't forget to stand up straight."

The car door opened and Pepper slid out. Bruce pulled the sunglasses on and followed, somewhat awkwardly. He was almost immediately blinded by camera flashes. He froze, dazzled by the lights and the roar of the crowd being held back by the NYPD. His heart leapt into his throat. They were taking his picture. No, he couldn't let them, Bruce couldn't be photographed- Pepper squeezed his hand and he abruptly remembered what he was supposed to be doing. Tonight, he wasn't Bruce Banner. He was Tony Stark.

Bruce squared his shoulders and lifted a hand to the assembled crowd. Loud cheers of "Iron Man!" broke out. He made his best attempt at Tony's cheesy publicity grin, and to his surprise, it felt more genuine than he'd thought it would. Pepper tugged on his hand and he moved up beside her so she could place her hand on his arm. Reporters, some real, some society, shouted questions at him as they passed. Their questions and shouts of "Mr. Stark!" blurred in his ears with the screams of "Iron Man! Iron Man!" from the crowd.

Once the cameras were safely behind them, Bruce removed his sunglasses and tucked them inside a pocket. "Not so bad, was it?" Pepper murmured, so only he could hear.

Bruce's heart was still pounding with the adrenaline rush of having to face so many people. To his surprise, it was almost exhilarating. There was no crushing weight of the Other Guy pressing against his eyes, trying to burst free. Nobody had ever cheered for him like that before.

They passed into the neoclassical marble grandeur of the Great Hall. Bruce blinked. His first thought was that it was the most beautiful space he had been in a long time. The space seemed filled to the brim with beautiful people; all designer tuxes and constellations of diamonds. Pepper nudged him with an elbow, and he realized he must have been gawking. Right, this kind of thing would be old hat to Tony Stark. "Sorry," he whispered. "It's my first time here."

He barely had a moment to collect himself before a bald man with a thick moustache and a vaguely arrogant air approached them. Pepper was immediately all business. "He's a board member," she whispered to Bruce. "James Gundersen."

"Ms. Potts," the bald man said cordially. "Stark."

Bruce smiled, and at the tiniest of nods from Pepper, shook the proffered hand. "Gundersen."

The man released his hand and moved off to speak with a nearby woman. Pepper guided Bruce expertly through the crowd towards the bar. She kept up a steady stream of murmured instructions in his ear. "Nod at him; you're not friendly but you respect each other. Don't look right; it's that gossip columnist Tony _hates_…Nine o'clock, older lady with the red dress, Lindy Donovan. She's a big donor. Wink at her as we go by; she'll love it."

He did as he was ordered and received a giggle in reply. The anxious knot in the pit of Bruce's stomach began to ease a little, despite the number of eyes following him across the room. "It's almost like you've done this before," he whispered playfully near Pepper's ear.

"You have no idea," she replied. "Although with you I don't have to give opposite instructions to get the right response."

Bruce smirked. Pepper collected a flute of champagne from the bartender. Bruce leaned against the bar, trying to look casual. It was difficult when it felt like every single eye in the vast room was fixed on him. The woman looked at Bruce questioningly. "Uh," Bruce said, trying to channel Tony Stark, "Give me a scotch; I'm starving."

Pepper hid a less-than-sophisticated giggle with a feigned cough. Bruce grinned at her as soon as the bartender's back was turned. She spotted someone over Bruce's shoulder and frowned. "Oh great… I need to head this one off. Half a mo'."

Bruce glanced backwards and followed her gaze to a man of medium height, with bluish eyes and sandy hair combed back precisely back from his forehead. For reasons he could not explain, Bruce instantly disliked him. He brushed the odd thought away and turned back to the bartender. She handed him a glass containing amber liquid. Bruce took a sip. Unfortunately everything still tasted like coconut, but the liquor warmed his stomach pleasantly nonetheless. He turned slightly so that his back was against the bar in order to observe the crowd, swirling his drink idly. Most of the curious eyes had returned to whatever they had been occupied with before he and Pepper had walked past. It was a relief. Nobody was afraid of him here.

Pepper's smile looked slightly strained when she returned to usher a surprised Bruce to the dance floor. He managed not to step on Pepper's toes during their single requisite dance, and she managed to keep him out of any social (or professional) disasters in the aftermath. The evening began to blur into a pleasant mixture of whispered conversation with her, simple pleasantries with everyone else, and scotch. After a while it was almost too easy to slip away into the galleries while Pepper was engrossed in conversation with another SI board member. Apparently nobody paid Tony much attention when he wasn't trying to make himself the center of attention.

Bruce had the galleries largely to himself. The attendees found the company and the bar in the Great Hall far more interesting than art they had probably seen many times. He relished the solitude. It was so…peaceful without the intrusive presence of the Other Guy on the edge of his consciousness, he thought while he admired a particularly fine El Greco. Even more liberating was the feeling that he didn't need to worry about control. He didn't need to hold himself in all the time. He could just…relax and enjoy himself, at least for a little while.

He finished the Spanish school and had just made it to the Dutch masters when his cell phone buzzed with a text message. Pepper was looking for him. Bruce smiled and tapped out a quick reply. He settled down to wait on a bench in front of a Vermeer until she could find him.

"Here you are," she said from behind him, smiling in amusement. "I've been looking for you for half an hour, Tony."

The "Tony" was just in case someone was watching. "Well, here I am," Bruce said, imitating Tony's cheeky grin.

Pepper took a seat close to him on the bench. She planted a kiss on his cheek and leaned her head on his shoulder. Bruce tried not to flinch at the contact, knowing it was for the benefit of any security guards who might be watching. Still, the gesture made the void in his heart left by Betty ache keenly.

"When Tony disappears at a party, I don't usually find him in the art gallery," Pepper murmured into his ear.

"It's not a problem, is it?" Bruce asked, suddenly concerned he had made a mistake. He looked around quickly to be certain that they were alone. Minus the security cameras, of course.

"The advantage to being an eccentric billionaire," Pepper told him, "is that you can be _eccentric_."

The physicist felt the corner of his mouth quirk upward. "I suppose so."

"I didn't realize you were an art person," she murmured, taking a quick look around the room.

"I wouldn't say I'm an art person, not like you or Steve," Bruce said with a shrug. "I appreciate the old masters, though." He looked back at the Vermeer. The scotch was making him philosophical, or at least more willing to share his thoughts. "Looking at them, it's like looking back in time. Like we do with astronomy, I guess. It's light from a three hundred year old room or a five billion year old supernova, seen through a filter…human or otherwise."

Pepper glanced up at him quizzically. "So why haven't you come before today?"

"What?"

"Before, you said this was your first time at the Met. You've been here for months, Bruce. Why haven't you visited?"

Bruce looked down at his unfamiliar hands. He ran a thumb over the MIT seal on Tony's class ring. "I, uh…I was afraid," he stammered. He swallowed hard. It sounded so stupid now, in his head. "The Other Guy. Most of the time it's fine, but there's always a chance…there's always a chance he'll come out by accident and I won't be able to stop him. He's- I've destroyed so much already…I just couldn't face the idea of having the destruction of cultural treasures on my conscience as well."

Mercifully, she didn't laugh at him. "It must be very different without…him."

"You have no idea," Bruce said fervently, before he could stop himself. "It's…uh, liberating." He ran his fingers over Tony's goatee thoughtfully. "This is the first time since the accident that I've been… _alone_," he added in a low voice. "I'd forgotten what it felt like to have my head to myself."

Pepper was silent for a long moment. "Bruce," she said softly. "Will it help Tony if I'm here while you two figure…this out?"

The physicist felt a pang of guilt, going on about himself when Pepper was worrying about Tony and the Hulk. He hesitated. He didn't want to hurt Pepper's feelings, but-

She guessed what he was thinking and smiled softly. "You can be honest. I just want to do what's best for him."

He took a half-deep breath. "No," Bruce told her. Pepper's face fell slightly, but she didn't say anything. "I mean, emotionally…yes, you help keep him stable and he needs to be stable right now. But you might be unintentionally distracting-"

She chuckled and Bruce felt his cheeks color. That had really just come out wrong. "Um, what I mean is, he'll worry," he amended hastily, cringing a little. "About, uh, hurting you if he transforms."

Pepper tucked a stray strand of hair behind her ear. "I understand," she said, straightening up with an air of determination. "I'll head to DC first thing tomorrow morning. That way if you need me, I'll be closer than Malibu."

* * *

_Please review! :) Your thoughts, comments, and questions are always fun to read._


	8. Chapter 8

_A/N: Finally free! Have a chapter, extra long because it's been a while. :) Many thanks to everyone who followed, favorited, and especially reviewed. I'm sorry I didn't get replies out to some of you; I'll do better this time! Also thanks to Red Tigress and Zarannya of The Beta Branch for betaing!  
_

* * *

**Entangled States**

Chapter 8

With Bruce and Pepper gone, the workshop was eerily silent. Tony sighed and leaned forward onto his elbows. He supposed this was what Banner felt like on a regular basis, he thought. Lonely, but never quite alone. The Hulk stirred in the back of his mind, as if to remind Stark of his presence. He slammed a mental door shut on the prying green fingers and tried to rouse himself to address problem at hand: building a device that would replicate the grenade's electrical explosion.

He'd thrown out the idea of building from scratch right away, because it would take too much time. Tony brought up the search function on one of the computers. Somewhere in the Stark Industries holdings, there had to be a device that would be capable of producing an electric discharge similar to the blast. Better to cannibalize something already developed.

With JARVIS' help, he soon had his search field narrowed down to fifty or so candidate devices. Tony squinted at the display with some irritation because he'd misplaced Bruce's glasses. Again. A few clicks, and the information was projected into the air. He enlarged it so he could read it easily, even with Banner's lousy vision. He went to rub his goatee, but his fingers just scratched across Bruce's stubble. Unfortunately, most of these devices just weren't going to cut it.

Tony unconsciously ran a hand over the place in his chest where the arc reactor usually sat. Skin, not metal, prickled under his shirt. He wondered if Pepper would make Bruce dance. That would be a sight to see.

_Bruce gasped and doubled over. He clutched the area around the arc reactor. His eyes closed and he exhaled with a hiss of pain. Tony looked away. He was familiar, so familiar, with the pain Banner was experiencing. Just thinking about it made him want a drink._

_His fingers, Tony's fingers, massaged the area around the arc reactor through his stiff white shirt. Tony knew it wouldn't help. There wasn't much that could; although a little scotch took the edge off. Now the questions were going to come. "How long did it take?" Bruce asked him, wincing. "How long did it take to stop hurting, Tony?"_

_Stark bit back a flippant reply. "It didn't," he said shortly. He could feel Bruce's eyes boring into him. "Not completely. First six months were the worst."_

_Bruce looked slightly sick. "You never said anything."_

"_And I'm not going to now," Tony snapped at him._

"_Bruce?" Pepper's call interrupted, to Tony's relief. "Where are you?"_

The beep of the keypad at the door yanked him out of his thoughts. Tony looked up and scowled as Clint Barton strolled inside, carrying something black slung over his shoulder. The archer found an empty table and dumped his quiver onto it. Arrows clattered across the surface.

Clint raised an eyebrow at his malevolent expression. He winced a little as the gesture tugged on his stitches. "Careful, wouldn't want Banner's face to stick like that."

"The hell do you want?" Tony demanded. He was not in the mood to deal with people, unless _people_ meant Pepper. Or even Bruce. He preferred to sulk privately, thank you very much.

Barton didn't even bat an eyelid at his hostility. "Quiver jammed yesterday," he explained, gesturing at the black bag. "Dunno why."

"What's it to do with me?" Tony snarled. He generally liked Barton, but he wasn't above taking out his bad mood on the agent. He felt the Hulk stir.

"Thought you might be able to give me a hand, shellhead. Since me and this quiver are keepin' your potentially green ass from destroying the city."

"You couldn't afford my rates," Tony said loftily. "Get out, Barton."

Clint's face hardened. "Look, Stark, I promised Banner I'd keep an eye on you. So you either can get over the fact that I'm gonna be here," the agent snapped, withdrawing a syringe from his back pocket and waggling it menacingly at Tony, "or not." Barton gave him a feral grin. "Just keep in mind that, unlike Banner, I got _no_ moral qualms about knocking you out and watching TV for the rest of the night."

Tony glowered at him defiantly. He even opened his mouth to argue, but he knew he couldn't win. Barton would just make good on his threat, and where would that get him? So Tony opted for surrender, but not without a parting shot. "Sorry to disappoint, my fine feathered friend, but the _Supernanny_ marathon was last weekend. You're out of luck."

Clint's puzzled look quickly broke into an amused smile. "How the hell- Right, Phil kept an eye on you for a couple days."

"So it's not a SHIELD thing? I thought it was a SHIELD thing. Aren't you guys basically supernannies for superheroes these days?"

"Nah, that was just Phil. I'm more of a _Dog Cops_ kinda guy," Clint said, choosing to ignore the jab at his employer. He chuckled fondly. "I forgot he used to do that."

Tony felt like dealing with sentiments even less than he felt like dealing with people. He raised an eyebrow and changed the subject. "_Dog Cops_? Seriously?"

"Hey, don't knock it 'til you try it," Clint retorted, gesturing at him with an arrow. He popped the bottom panel off his quiver and let out a hiss of frustration. "God, sometimes I hate this thing."

His professional curiosity got the better of him. Tony craned his neck to see a complicated spiral of trick arrow heads. A set of gear-like plates held them in place. He couldn't make out the entire mechanism, but it looked like the gear-like plates rotated through different tiers of the arrowheads, allowing Barton to switch between them as needed. Clint noticed him staring and smirked. "Sure you don't want to give me a hand?"

Tony looked hastily back at his own project. "I don't need a babysitter, Barton," he complained. There was a rumble of approval from the back of his mind. He quashed it.

"Not your call, man," Barton shrugged. "Cheer up. I ordered Chinese."

Tony's stomach gave a hungry grumble. The situation was still less than ideal, but Chinese was an acceptable peace offering. At least the thought of food didn't make him feel nauseous any more. Tony turned back to his display. "There's a set of precision tools in the drawer to your left."

"Thanks," Clint said.

Barton's company proved to not be so miserable after all, Tony decided, even though the SHIELD agent hogged the lo-mein. He was careful to keep to himself and out of Tony's way while he tinkered with his quiver. Aside from the occasional yelp and muttered curse that accompanied a pinched finger, he didn't speak, and for that, Tony was grateful.

He sighed while he flicked through yet another set of holographic files of candidate equipment. Tony squeezed his temples tiredly. He needed to find Bruce's glasses; the dull headache that had been his constant companion all day was slowly building into a persistent throb. It seemed to hover with the Hulk, just behind his eyes.

"Stark." Tony glanced up. Clint was watching him. The agent's expression was inscrutable. He jerked his head to the side. "Over there."

Tony glanced to his left and saw the wayward glasses sitting on top of a haphazard sheaf of Bruce's paper reprints. He resisted the urge to look behind him. Damned if it didn't feel like someone was lurking over his shoulder. He knew it was the Hulk, but it was still unsettling, and it interfered with his concentration. He shot Barton a questioning look.

The archer shrugged. "I spend a lot of time around Banner."

The engineer retrieved the glasses and put them on. Tony blinked experimentally and looked back at the current set of schematics. Hmm, this one might actually do it. He plucked the files from the air and deposited them into the virtual box that represented his private drive on the Stark Tower server.

"JARVIS," he said aloud. "I want top level encryption on these files; access limited to myself or Bruce." Out of the corner of his eye, beyond the rim of Bruce's glasses, he saw Clint's slightly blurry head look up. Tony ignored him. Nobody employed by SHIELD was going to have access to this work, period. "Put in a request to have the prototype of, uh, SI-45601 brought out of storage and to the workshop. Top priority. I want it tomorrow morning at the latest."

"_Very good, sir. Working on another top secret project, I see?"_

"This one's a little less exciting than the last one, J. Oh, have them strike the Project Hulkbuster designation off it before delivery."

The swipe of his hand projected the detailed schematics into the air. He studied them, rubbing Banner's prickly chin thoughtfully. It was going to be tricky to rework, but it was definitely doable. Tony brought up his editing interface with a twist and flick of his wrist and began trashing unnecessary pieces of the machine. The truck mount was the first to go. Obviously he'd have to physically dismantle it after it was delivered, but it was good to have some sort of plan before he started ripping real things apart.

"Looks like a giant cattle prod," Clint commented from across the room. "That one of Ross' toys?"

Tony's hands instinctively balled into fists at the sound of General Ross' name. Something green roiled in the back of his mind. Clint's eyes narrowed. Tony suddenly realized that he was snarling. _Cut it out_, he directed at the Hulk with some irritation. He hastily rearranged his borrowed face and shot the agent a _look_. "Don't tell Banner."

Clint seemed dubious. "He'll figure it out," he predicted, but he didn't refuse Tony's request.

The engineer looked back at his schematics and frowned. Honestly, the building was going to be the easy part. He pulled up Banner's data and displayed it beside the specifications for the…giant cattle prod. Programing the control system was going to be a lot more difficult. The level of precision control required to exactly replicate the blast was somewhat appalling. It would be a stretch of even Tony's considerable skill. He yawned and stretched in his seat.

Breaking his concentration was a mistake. Clumsy green fingers had invaded his thoughts; poking and prodding through everything. Tony finally snapped. "Knock it off!" he shouted. He gripped either side of his head and winced as the pressure behind his eyes mounted. But the green just flared brighter with his frustration. He could feel his breath quickening to a steady pant. The Hulk pressed forward, pushing relentlessly against Tony's borrowed eyes.

There was a blur of motion out of the corner of his eye. Clint was on his feet. Tony knew he had the syringe grasped in his hand. "Stark," he warned.

Tony gritted his teeth. No. He was _not _going to spend any more time drugged into a coma. He wasn't going to let the Hulk win. He wasn't going to make Bruce leave. He forced himself to take a deep breath and let it out slowly. The green mass seemed to subside. Encouraged, Tony did it again. Eventually he tried one of the rhythms Bruce had shown him, and to his grudging surprise, it helped.

It felt good to be able to really _breathe_ again, without the arc reactor cutting painfully into his chest. As far as simple pleasures went, Tony supposed _breathing _was as about as simple as one could get. The thought made him chuckle. He relaxed, and the Hulk slunk back into the recesses of his consciousness.

"You good?" Barton asked.

Tony rumpled Bruce's thick hair and squeezed his temples against the throb in his head. "Yeah, fine," he muttered. He fished around on the desk for a bottle of painkillers and swallowed a couple of them dry. His whole body seemed to ache along with his head. Well, Bruce had said he'd feel lousy for a few days. Tony leaned forward onto the worktable, pushing Bruce's glasses up off his face and pressing his palms to his tired eyes.

"_We don't have time for this now," Bruce sighed. He tugged on his collar uncomfortably. "I better go."_

_Tony suddenly couldn't hold back the words any longer. "Look," he blurted. "She doesn't know." _

_Bruce's eyes, Tony's eyes, widened with surprise. He released the arc reactor and slowly lowered his hand. "What?" he exclaimed incredulously, "You didn't even tell _Pepper_?"_

_Pepper's voice interrupted again. She sounded closer. "Bruce? We need to leave!"_

_He glanced frantically towards the door. She couldn't see. She couldn't see, not ever. Tony couldn't allow it. "Just don't let her see," he hissed at Banner._

"_Tony…"_

"_Please, Bruce!" The desperation in his voice surprised even Tony._

"_Fine," Bruce agreed under his breath, but with a look that clearly said: _this isn't over_. "In here, Pepper!" the scientist added in a louder voice._

_Tony hastily rearranged his features into a bland smile as Pepper entered the room. Bruce was fumbling with his bowtie to hide his agitation. "You look fantastic," Tony told her. She smiled broadly and moved to help Bruce figure out his tie._

Tony dragged his head out of his palms. He glanced back at the schematics and suddenly, he didn't feel like working anymore. He just felt…drained. He looked up at the clock on the wall. The night was still young, but he was already so tired. The Hulk stirred restlessly. Tony visualized pushing the monster away as he pushed himself away from the work table.

"I'm going to bed," he announced for Barton's benefit. Clint glanced at the time with surprise. "Sure you don't want to jump in with me, just to be safe? You _did_ tell Banner you'd keep an eye on me," Tony added, just to be an ass.

Clint refused rise to his bait. If anything, the archer looked a little worried. "G'night, Stark."

* * *

Tony woke a few hours later with a strangled cry, panting and tangled in sweaty sheets. The darkness of their bedroom was absolute without the glow of his arc reactor. It was disorienting. Now that he was conscious again, he couldn't remember what the nightmare had been other than he had been running. Running, always running, from something dark and looming and terrible.

He extracted himself from the claustrophobic tangle of bedclothes and sat up. Tony ran his hands through Banner's curly hair; now dampened with perspiration. It felt _wrong _and he shuddered. A glow appeared under the door. It opened and Pepper appeared in the doorway. She froze there for a moment, as if surprised to see what appeared to be Bruce Banner in their bed.

"Tony?" Pepper's soft voice asked. He'd never heard anything better in his whole life. "Are you all right?"

Tony sagged back against the headboard, still panting. The Hulk was roiling in the back of his mind. He squinted as the bright light lanced into his eyes. "Yeah," he choked. He tried to take a deep breath. "Just a dream."

JARVIS brought the bedroom lights up automatically when she entered, but the AI kept them low enough that Tony didn't have to squint. There was a pair of _thunks _as Pepper dropped her heels to the floor. She'd taken her hair down, but she was still wearing her formal dress. It rustled softly as she moved to sit on the edge of the bed beside Tony. She hesitated again for a fraction of a second before leaning against his shoulder. He took her hand and she wove her fingers between his.

"I wasn't expecting you to be in bed so early," she told him.

"Long day," he murmured. He inhaled the scent of her hair mingled with Chanel, and finally, he felt himself begin to relax. The monster retreated. "How'd it go?"

"Understatement of the year," Pepper said fervently, but she smiled. "It went well. I think Bruce had fun."

"Bruce Banner? _Having fun?_" Tony snorted, and Pepper chuckled. "I'll believe it when I see it."

She sobered slightly. Tony glanced at her questioningly. Pepper hesitated before she spoke. "Dr. Killian was there."

Oh god, the last thing he wanted to talk about now was the geneticist._ That_ debacle was a topic for another night. "Don't," Tony said warningly. "Don't start-"

"I wasn't going to," she interrupted, sounding hurt and drained. Pepper looked down at her manicured nails. "I put him off. I just…thought you should know."

They sat in silence for a moment. Tony pinched the bridge of his nose, trying to release some of the pressure behind his eyes. She was just trying to help him and he had thrown her concern back in her face. He suddenly felt awful for all the things he put this woman through. "Sorry, Pep. I just...it's been a hell of a couple days."

She squeezed his hand to show she wasn't mad. "I know it's a lot," Pepper told him softly. "Do you want to talk about it?"

"Not really."

"Okay."

The pressure on his hand released and she gingerly worked her fingers out of his grasp. "What? Where are you going?" he asked, alarmed. "Don't go."

"_I_ need to get some sleep. _You_ need to get some sleep. It has been a _very_ long day," Pepper sighed, taking care to avoid his pleading look. His heart sank a little. "Tony, I understand that it's you in there, but I just…can't."

"What, not while I'm a rage monster?" he asked, with more bitterness than he'd intended.

"Not while you're _Bruce_!" she exclaimed.

Okay, Tony had to admit she had a point there. The corner of his mouth quirked upward. "Is it still considered hulkblocking if the Hulk's not actually here?" he quipped.

Pepper giggled and swatted him lightly on the arm. She got to her feet and brushed her hair back behind her ears. The earrings he'd given her for Christmas bobbed delicately. She walked around to the other side of the bed to retrieve her favorite pillow. "I'm heading to DC first thing in the morning."

"But you just got here!" Tony protested.

She hugged the pillow to her chest, and her face softened. "I know. I'd rather stay. But I'm a distraction, and the last thing you and Bruce need right now is a distraction. I'll pop in tomorrow before I leave. Good night."

Clearly, she'd made up her mind. Tony wouldn't get anywhere other than irritated trying to convince her to change her decision. "Night."

Pepper pulled the door closed after her. JARVIS dimmed the lights again. Tony rolled onto his side and rearranged the pillow under his head with a sigh. He could hear her bare feet padding towards the guest room. Deep in his heart of hearts, he was relieved to see Pepper go. This way he wouldn't have to worry about hurting her if he transformed again. It wasn't exactly a comforting thought, but it would have to do.

* * *

_Please review! I promise I'll write back this time! :)_


	9. Chapter 9

_A/N: Oh my, another long chapter! Thanks to everyone who reviewed, favorited, and followed! Also huge thanks to Red Tigress of The Beta Branch for beta reading. This chapter has a **trigger warning** for suicide (mentioned) for safety.  
_

* * *

**Entangled States**

Chapter 9

Bruce Banner could not remember the last time he had enjoyed a cup of coffee. This wasn't even _good _coffee, he reflected as he savored a sip of the hot liquid. Just whatever he'd managed to pinch from Clint, who had in turn pinched it from Natasha's apartment. He closed his eyes and inhaled deeply, enjoying the distinctive aroma that now permeated his apartment.

Already, the dull ache in his head he'd awoken with was beginning to lessen with the addition of caffeine to his bloodstream. Bruce yawned and stretched. The rush was…refreshing. Not that he really needed it; the scientist had slept surprisingly well after getting home from the charity gala. Once he'd figured out how to block the light from the arc reactor, anyway. Even his subconscious had been kind. His dreams had been filled with the thrill of flight and not a single hint of green.

Bruce was just contemplating a second cup of coffee (really, he might as well enjoy it while he could) when a sharp pain lanced through his chest. He bit his tongue to keep from crying out, even though there was nobody around to hear him. It was a different sort of pain than the near-constant dull ache around the arc reactor. He rubbed his hand over the chestpiece with a frown. Another pain followed, less sharp, but ebbing into an uncomfortable, persistent tingling. He increased the pressure in his fingers, kneading the skin around the metal rim of the reactor. He tried to relax.

The physicist glanced at his watch and sighed. He didn't want to bother Tony with something trivial, but the tingling was rapidly becoming bothersome. There was something about it that just didn't seem _right_. Maybe it was worth asking Tony about. The billionaire could be an early riser when it suited him, and Bruce knew Pepper had left quite early. The scientist set his empty mug in the sink and headed for Tony's workshop.

The question of whether or not Tony was in the workshop was answered by the very loud music emanating from below. Bruce could hear it all the way in the elevator, even through the glass wall. He punched his code into the door. Blaring rock music from a band he didn't recognize assaulted his ears as it swung open.

"Tony?" he called inside, raising his voice to be heard over the pounding music. There was no response. Bruce winced a little and resisted the urge to cover his ears. "JARVIS, lower the music volume, please."

The volume abruptly decreased to a reasonable level. As expected, he got immediate results. "Hey, don't turn down my music!" Tony shouted. His voice came from the far side of the workshop, across from the alcove devoted to his armor. Bruce glanced at it fondly as he strolled over to find the inventor.

"I could feel the reverb in the elevator," Bruce remarked. "Feeling better?"

"You," Tony stated, looking up and rotating one of the computer monitors to that it faced the physicist, "are too boring to be Tony Stark."

Bruce glanced at the screen and rolled his eyes. It was a gossip website. A photograph of him and Pepper getting out of the car outside the Met last night was splashed across the front page. He looked rather deer-in-headlights even behind Tony's sunglasses, but Pepper looked good. The headline read:_ Stark Raving Sad? Billionaire Strangely Subdued at Charity Gala_.

"Really, Tony?" he grinned, despite the painful tingle in his chest. "Googling yourself again?"

"Had to see how you did last night," Tony told him. He gestured to the monitor. "Front page, good. Reasonable red-carpet behavior, although you lost points for no quality soundbites. The lack of debauchery will count against you. You are _much_ too boring to be Tony Stark. But as you kept Pepper happy, I'll bump you up to a B."

"Thanks, I think," Bruce replied, trying not to wince.

"So you going to stand there, or are we going to get to work?"

"Uh, I think something's wrong with the arc," Bruce said, a little more breathlessly than he'd intended. The hitch in his voice caught Tony's attention, and for the first time, Tony really _looked_ at him. It felt a little odd to be examined by his own eyes.

"What's it feel like?" Tony asked, cocking his head appraisingly.

"Tingly," Bruce said with a grimace. "Then it gets sharp. It's been getting more frequent."

It was a terribly vague description, but Tony nodded. "Oh, that. Easy fix. JARVIS?"

"_The seven o'clock connection between the reactor and the baseplate is slightly bent,"_ the AI said. Tony snapped his fingers (showoff, Bruce thought) and a schematic of the arc reactor and its casing flared to life in mid-air. Tony spread his hand apart and the pieces unraveled into an exploded view. The damaged contact was highlighted in orange._ "I informed Doctor Banner-"_

"Yeah, yeah, I get it," Tony interrupted. He glanced at Bruce and gestured at the worktable. "Sit."

"What? Why?" Bruce asked nervously. He suddenly realized that he had never seen Tony without the arc reactor. He knew why it was there, of course, and the thought was not reassuring.

"I need to pop the reactor," Tony explained, rotating the hologram of the arc reactor and squinting at it. He cast around on the table for Bruce's glasses and put them on. "Happens all the time," he added, at Bruce's anxious look. "Ten second fix."

Bruce hesitantly hoisted himself onto the table. He glanced over his shoulder to make sure nobody else was in the vicinity before he unbuttoned his shirt, ignoring Tony's derisive snort at his modesty. As soon as the reactor was exposed, Tony grabbed the edges and gave the whole thing a sort of jiggle twist. The arc reactor rotated in the cavity. Bruce jumped as he _felt_, rather than heard, something _click_ deep in his chest.

"Tony, what-" Bruce started, alarmed, but it was already too late. The arc reactor disconnected and pulled free.

It felt like Thor had slammed Mjolnir into his chest. The air seemed to evaporate from his lungs. Sudden weakness seemed to flood his body. Bruce gasped and gripped the edge of the table so he would not crumple forward. It was all he could do to stay upright. Coldness invaded the empty cavity, sending unpleasant chills down his spine. He managed to force a ragged breath into his lungs just as he was beginning to see stars.

Tony coolly turned the arc reactor over in Bruce's hands. Bruce did not understand how he could be so calm. His heart was racing now, and there was something _wrong_ about the feeling. Sharp little prickles of pain were beginning to radiate outward from his heart. His whole body was trembling with the effort of staying upright. The engineer frowned a little and pressed a small, rubber-tipped tool against one of the little metal tabs sticking out from the end of the arc reactor.

"All points need to make contact in order for it to maintain optimum conductivity to the baseplate," he explained, for Bruce's benefit. "If one of them gets loose, magnet efficiency decreases."

"Fascinating," Bruce croaked.

Tony glanced up at him and laughed. "You look like Pepper the first time she saw the arc." He held the reactor up to eye level. Blue light glinted off the lenses of Bruce's glasses. He adjusted the tab again. "Don't worry, you've got a few more minutes before you go into cardiac arrest."

Bruce's heart gave another unpleasant jolt, this time out of fear. "_What?_"

The engineer held out the arc reactor. "Just push until it makes contact, then twist until it clicks."

Bruce accepted the chestpiece with a shaking hand. It felt warm and inordinately heavy. He shoved it into the gaping hole in his chest as directed. The change was instantaneous. The prickles in his heart increased momentarily, but the small pain quickly began to fade again. The crushing weight lifted from his chest. He sucked in several greedy breaths and energy flooded back into his limbs.

The physicist slid down to the floor with an ungraceful thump. His hands were still shaking as he went to button his shirt. He leaned back against the table and looked up at Tony after he finished.

Stark scowled. "Don't give me that look, Banner."

"Tony, we need to talk about this. I know now. You can't just pretend like nothing happened."

"Why not?" Tony turned dismissively back to whatever unfortunate machine he was dismantling. Bruce hadn't gotten a good look at it yet. "We're working, not talking."

"Tony-"

"Computer to your right. I started a model of the explosion; I need you to finish it," Tony told him. He wasn't looking at Bruce. "Fucked up as it may be, I want my body back."

Bruce pinched the bridge of Tony's nose. "You should know by now that if this whole team thing is going to work-"

"I'm sorry, is _Bruce Banner_ lecturing me about teamwork?"

"I'm serious!"

"Taking it seriously," Tony said, turning back to wag a facetious finger at him, "does not make it hurt any less."

Bruce allowed himself to feel chastised for about two seconds before giving in to his irritation. Tony could be absolutely infuriating when he wanted to be. He bit back his frustration with the billionaire. "Does _anyone_ know about this?" he demanded. "About how vulnerable you really are?"

Tony flinched as if from a physical blow. His face abruptly darkened. His hands balled into fists. "Just _drop it_, Bruce," he snarled, with such venom that Bruce instinctively took a step backwards.

Bruce swallowed hard. It bothered him to think of Tony as vulnerable. Apparently not as much as it bothered Tony, though. "This isn't the kind of thing you keep to yourself, Tony!" Bruce exclaimed, before he could stop himself. Reflexively, he passed a hand over the arc reactor. "I get that you don't want to tell Steve and them, even though I think it's stupid, but _Pepper?_"

"And what exactly would you know about it?" Stark spat viciously. He turned back to the machine and ripped something off of it with what seemed like an inordinate amount of force. "Mister I-can't-die-no-matter-how-hard-I-try?"

It was such an unfair thing to say that Bruce just stared at him for a moment, open-mouthed. "Fine," he snapped, stung by Tony's words. "Forget it." He sighed and ran a hand through his short hair in lieu of taking a deep breath, trying to get a grip on his temper. He felt drained. "What did you want me to do again?"

The inventor did not look up. "I need a model of the explosion based on your data, accounting for resistance in the armor, energy loss in atmosphere, anything that would attenuate the electrical discharge. The control box will have to replicate all of it."

Bruce took a seat at the computer. If there was anything the nuclear physicist was good at, it was computer modeling. He pulled up Tony's file, venting his anger by stabbing at the monitor with a little more violence than was necessary. He automatically went to push his glasses up on his nose. His finger just skidded awkwardly along the bridge of Tony's nose, because there weren't any glasses to push. It would have been funny if he hadn't been so irritated with Stark.

It felt good to concentrate on something that wasn't the Hulk or Tony, Bruce thought while he typed. He determinedly ignored the billionaire for a few hours. Yes, it was juvenile and petty, because he knew there was nothing Tony hated more than being ignored. Bruce thought it served him right. The silence was broken only by the metallic _clink_ of Tony's tools and the soft click of a keyboard.

"Rhodey knows," Tony said suddenly, out of nowhere.

Bruce blinked out of his coding trance. Apparently he wasn't the only one who had cooled off over the past few hours. "What?" he asked, peering at the billionaire through the monitor.

"Rhodey knows," Tony repeated, his voice deliberately flat. He still did not look at Bruce. Instead, he reached for a bottle of over-the-counter painkillers and knocked back a handful. "Found me after Stane- Yeah. He's seen what happens when the arc fails."

Bruce frowned. One sleepless night, Tony had gotten drunker than usual and related the story of how Obadiah Stane had paralyzed him and forcibly ripped the arc reactor from his chest. Apparently he'd left out some of the details. The physicist had to admit telling Rhodes was a step in the right direction, but he wasn't exactly an Avenger. Bruce leaned back in his chair. "What happens if it fails, Tony?" he asked quietly.

Stark looked like he was considering making another flippant remark, but to Bruce's surprise, he did not. "The shrapnel starts to move again," he continued in that same emotionless tone. "I've got about twenty minutes to find an alternative power source for the electromagnet before I go into cardiac arrest."

Bruce suppressed a shudder. He had no idea it would happen so…quickly. "And you _didn't_ tell Pepper?"

"She knows I can't take it out."

"But nothing else," Bruce stated, thinking of the promise he'd made to not to let Pepper see how much the chestpiece pained him. He rubbed it again.

"Nope," Tony said. He glanced at something to Bruce's left. "Hand me that screwdriver, will you?"

Bruce studied him for a moment. It was a start. He decided to quit while he was ahead and passed the screwdriver to his friend. Tony was standing half-bent over an open access panel on a…thing. He shifted slightly to one side, and Bruce got a good look at it for the first time. To his dismay, it vaguely resembled a giant cattle prod. Well, that was one way to get a massive electric shock, he thought.

"Where did you find this thing?" he asked, prodding the base of the device with his toe. Tony had bolted whatever it was onto what looked like a spare chassis for one of his robotic arms. He was actively dismantling it, laying out crucial components on an adjacent worktable and discarding whatever he deemed unnecessary. Bruce frowned a little. He had a nagging suspicion that he had seen something like it before.

Tony glanced up and raised his eyebrows significantly at the scientist. Bruce thought for a moment and it suddenly dawned on him. He _had_ seen the giant cattle prod before. Except it had been mounted on a truck, and accompanied by several angry soldiers. He'd been green at the time. "Oh," Bruce said, with a little surprise. Now that he looked closely, there was a bar of fresh paint covering what looked like a serial number on the device's side. "_Oh_. I, uh, thought it looked familiar."

The engineer's expression became questioning, and Bruce chuckled at his concern. If he were currently sharing headspace with the Hulk, it might be a bigger issue. But he wasn't, and Tony himself seemed to be doing okay. "It's fine," he reassured his friend. "Unlike General Ross, I appreciate irony as much as the next rage monster."

Tony grinned.

Once the initial shock of the switch subsided, they quickly fell into a loose routine. Bruce and Tony spent most of their waking hours in the workshop, working on the modifications to the machine. Tony handled most of the building (even though he was the more efficient programmer), while Bruce focused on the modeling and the computer control system. It didn't take long for Tony to fall into one of his inspired (manic) periods and his energy kept both him and Bruce going. Clint declared the whole situation too geeky for the likes of him, but he dropped by periodically to chat with Bruce or crack wise with Tony. He never went far from the tower, however.

"Why don't we just…take a day and go up north?" Tony said suddenly, one afternoon a few days after the accident. "We can take my jet. Nice and easy."

"What?" Bruce asked, glancing up from his computer. The machine was only about half finished, but Tony had been determined to test what they had built so far. "Now? I thought we were going to try this crazy contraption."

"It's only crazy if it doesn't work," Tony told him. He set down his soldering iron and unscrewed the top of a pill bottle. He shook several pills into his palm and swallowed them dry. "Might be nice to just take a day and let loose. Somewhere way up north, where nobody will get in the way."

The physicist raised an eyebrow at him. While his interpretive skills were improving, Bruce still had a difficult time decoding Tony's expressions through the blur of own features. He couldn't tell if Tony was being serious, just being Tony, or if there was actually some kind of problem that Tony was not telling him about. "What do you mean, we?"

"You and me. I can let the big guy out to play, and you can goof around in the suit. There is not nearly enough goofing in your life, Banner."

Bruce shot a longing look at the armor. The idea was tempting. Every night since the explosion, he had dreamed of flying. Not the usual floating sensation, but the roaring across the sky at full thrusters variety of flight. It was refreshingly different from his usual nightmares. Bruce certainly wouldn't mind getting to fly again. But no, they had work to do. He pushed the thought of his own pleasure from his mind. Besides, it seemed odd that Tony would willingly undergo the pain of transformation again.

"I think SHIELD might notice if we both just upped and left town," Bruce said diplomatically. "Especially once you let the Hulk out."

Tony looked crestfallen. He made a final adjustment inside the machine and slammed the access panel shut. "Oh. Well, it was just an idea."

Bruce studied him through his monitor. The engineer occupying his body looked exhausted. There were dark circles under Banner's soft eyes. That wasn't entirely unexpected; they had been burning the candle at both ends. But given the way Tony was knocking back painkillers and his sudden interest in letting the Hulk out, Bruce thought there was cause for concern.

"Is everything okay?" the physicist asked.

"Yeah, yeah, everything's fine," Tony said, with a rakish grin. There was a strained quality about the expression that bothered Bruce, but he didn't feel like trying to worm the reason out of Tony at the moment. Maybe after the test. "Ready when you are."

"Okay," Bruce replied. He initialized the control program, and at Tony's nod, flipped the switch. The machine hummed to life. Bruce watched as a progress bar filled as the charge built up. When it reached the 50% mark, he clicked a button on the screen to signal the discharge.

A brilliant flash of blue-white energy leapt from the tip of the machine to the grounded target. Tony took a step forward to take a closer look, squinting through a pair of his sunglasses. A hot smell suddenly filled the air. Before Bruce could do anything about it, something seemed to explode. He threw his arms up to protect his face. Closer to the source, Tony was blown off his feet. His body impacted the floor with a sickening _thud_.

"Tony!" Bruce cried, and slammed the switch back down. The machine powered down with an electronic whine. Bright spots danced across his vision. He ran to his friend's side. To Bruce's incalculable relief, he could see the engineer's chest rising and falling. He dropped to a crouch beside him. "Tony? Are you all right?"

Tony groaned. Bruce felt his heart clench. He reached out to grab Tony's arm, to try to roll him onto his back so he could see the damage. His body seemed to convulse, and for a moment, Bruce was terrified that something was horribly wrong. Tony groaned again.

"Get…back!"

There was a terse, guttural quality about his voice, Bruce's voice, that the scientist suddenly recognized. His heart dropped into his stomach. He pulled his hands away from Tony's arm and watched in horror as the muscles seemed to writhe and shiver of their own accord under his shirt.

Something _was _horribly wrong. Tony was transforming again.

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_Please review! :)_


	10. Chapter 10

_A/N: Egads, sorry this is so late, dear readers! Real life has been crazy._ _Many thanks to RedTigress and Nonyvole of the Beta Branch for their help in this chapter together! Also thank you to everyone who has favorited, followed, and reviewed. :) Without further ado..._

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**Entangled States**

Chapter 10

The force of the impact drove the breath from Tony's body. Stars burst before his eyes when his head cracked against the floor a split second later. Time seemed to slow. He lay there for a moment, looking up at the ceiling with the eerie calm of shock.

Adrenaline flooded into his veins as he tried to force oxygen into his protesting lungs. A strangely detached corner of his mind noted the feeling of his heart revving up while he choked and gasped. Pain from the blow to his head and back mingled with growing panic from his inability to breathe. Tony had to brace himself. He knew what was coming; he'd seen what happened when Bruce was injured and the Hulk came out roaring to defend him.

Finally, he managed a shallow breath, and then another, and another. Soon he was panting. An acid tingle he had felt only once before was beginning to spread across his brain. He tried to pull himself up on one elbow. Tony wasn't going to let—

The second blow smashed into him with all the force of a green wave. Tony curled in on himself. Somehow he dragged his body onto its side to try to defend against the flood, but there was nowhere to hide. He squeezed his eyes shut as the Hulk slammed into them. A groan escaped his clenched teeth as _green_ began to flood every aspect of his consciousness. The sear of acid flowed from his head, burning down his neck and spine. His fingernails cut into his palms as his hands clenched into fists.

"Tony!" Bruce whispered. His voice seemed very far away, drowned in the _green_. "... All right?"

The Hulk roared at the sound of his voice, the impossibly loud sound reverberating through Tony's tortured skull. He yelled with pain, but a choked moan was the only sound that came out. His blood felt like it was on fire. Muscles were rippling all across his body as they made contact with the spreading acid. Suddenly there was a hand on his shaking arm. Bruce, he realized dimly. Only Bruce would be crazy enough to touch him now. A bright flicker of fear pieced through the green fog. No, he had to get away. The Hulk could kill him.

"Get…back!" Tony snapped through clenched teeth. There was a horrible alien quality about his voice, _Banner's voice_, that terrified him.

The hands released Tony's arm. His muscles, _all_ his muscles, seemed to writhe and shiver of their own accord under his clothes. His skin crawled. His body twisted and convulsed against the hard floor as the monster tried to exert control over Tony's body by force. He was smothering between his brain and the bones of his skull.

Far away, he could hear Bruce's voice. "JARVIS…Agent Barton…"

_NO,_ the Hulk roared, louder this time. Green-hot rage and frustration burned through the engineer. _MOVE PUNY HUMAN. _Green fingers were ripping through his mind, smashing against Tony's mental knuckles to try to get him to loosen his grip and let the Hulk out. But Tony clung gamely to his consciousness. Another spasm arched his back upward and dragged their head out of his hands. This time he couldn't help shouting with pain. The spasm ended and Tony clutched his throbbing head, gasping during the slight reprieve. Banner's curls were soaked with sweat. He couldn't hold out much longer.

"Tony!" Bruce said. Tony knew he was shouting, but the scientist's voice sounded increasingly distant as he tired. "Have…fight!"

A sick thrill of anticipation blossomed in his stomach. The Hulk sensed his growing weakness. Tony shuddered and his muscles convulsed inwards. His skin was beginning to feel tight. One knee collided with his lip and he tasted blood. He cried out again, out of fear more than pain. He just wanted out of this nightmare and back into his own body. His consciousness was dribbling through his fingers. He _wanted_ to let the Hulk out. At least then he wouldn't have to remember any more of this hell-

_No,_ he screamed at himself over the Hulk's roar of approval. _No!_ If he transformed, he would smash the machine. He would smash _Bruce_. Damned if Tony Stark was going to let that happen.

He beat one fist into the floor, then the other. Reasserting control over some part of his body encouraged him. The finest of cracks appeared in the impenetrable green murk. His fist hit the floor again and the crack lengthened. The Hulk howled with anger and tried to smother Tony in his head but even he couldn't snuff the tiny ray of hope. Tony forced himself to take a full breath.

"…to focus!" the physicist shouted. He was still too close for comfort, but Tony sensed he was out of arm's reach. "Focus…me. Focus on my voice."

Tony managed to get to his knees before the Hulk sent him sprawling again. He refused to stay down and willed his burning limbs into position. He took a ragged breath and let it out as slowly as he could manage. The hard floor bit into his kneecaps but he didn't care. His fingered splayed on the concrete. He kept his eyes squeezed shut, reluctant to give the Hulk any means of escape.

Boots skidded shrilly across the smooth floor. "_The HELL?_" Barton's surprised yelp cut through the green haze. "Banner—"

"Wait!" Bruce cried. Tony could hear all of Banner's desperate words now, even if they were still a little…distant. "Just…wait! Tony, I know you can do this. _Focus_. Breathe first. Just like we practiced. The rest will follow."

He clung to Banner's voice like a lifeline. The words themselves didn't even process; he followed Bruce's instructions without thought or hesitation. There wasn't anything else, besides Tony and the Hulk and his voice. Time had no meaning. His heart rate began to slow. The acid wave receded, leaving his body weak and shaking. Bit by agonizing bit, the Hulk's grip on his mind began to loosen. The green fog dissipated. Finally, the monster let Tony go. Tony slammed his mental door shut after him. Good riddance.

Tony opened his eyes. The workshop lights were uncomfortably bright. Bruce was looking down at him, kneading his fingers together anxiously. His face was crinkled with concern. Stark was too exhausted to even feel relieved. "Please don't make me do that again."

Bruce laughed much more than he should have, giddy with relief and a little bit of pride. He reached down to help Tony haul himself to his feet. His trembling muscles screamed in protest. He hadn't meant it to be funny. But he was Tony Stark, so everyone expected him to make a joke. _Especially _when things weren't funny. The engineer leaned weakly against a worktable. He reached up to squeeze his temples, feeling utterly drained. Barton peeled himself out of the doorway and strolled over to join them. His bow was slung over one shoulder.

"I knew you could do it," Bruce grinned. The quiet pride in his voice slammed Tony in the gut. The only thing he had done was almost Hulk out. The rest was all Bruce. Tony glanced away, embarrassed. "Are you all right?"

Tony shot the scientist a withering look from under his hand. He released his temples and dabbed at his split lip with his sleeve. Out of the corner of his eye, he saw Barton smirking.

Bruce chuckled knowingly. "Sorry, silly question. Why don't you go take a break? I'll deal with the machine; see if I can figure out what went wrong."

Tony opened his mouth to protest, out of habit more than any real reason. Bruce raised an eyebrow at him. Tony _was_ tired. He shut his mouth and gingerly levered himself off the edge of the table. Barton set his bow down and hiked himself up onto the table nearest the machine. His eyes followed Tony as the engineer headed stiffly out of the workshop. He was hiding behind one of his blank Agent Barton expressions. Tony wondered what he saw.

"You should probably incinerate that shirt," Bruce called after him.

Right, the whole irradiated blood thing. Tony rolled his eyes. Banner was being paranoid; his lip hadn't bled all that much and the reddish smear on his sleeve was quite small. He waved to show that he'd understood and limped outside.

The elevator buttons swam in and out of focus as he selected the penthouse. Tony closed his eyes and sagged against the glass, trying to ignore the disconcerting feeling. The dull throb behind his eyes that had been his constant companion since the accident was building again. He'd hoped nearly hulking out would relieve some of the pressure, but apparently it did not.

The penthouse was blessedly dim and quiet. Tony couldn't bring himself to face the empty bedroom, so he poured himself a glass of water and headed for the couch. He remembered to kick his shoes off before his feet touched carpet. He studied Bruce's stocking feet morosely. Shoes that had been in the workshop weren't allowed on the carpet. Pepper would be so proud that he remembered.

God, he missed her already.

Tony drained the glass in one long gulp and rolled it back and forth across his forehead. It soothed his hot skin. He should probably eat something, but he couldn't summon the energy to get up again. He could barely summon the energy to set down the glass and press Bruce's palms to his eyes. He felt guilty and a little sick.

How did Banner _do_ it?

He could deal with the other voice, the intrusion into his mind, the maddening ache in his head. Even the disturbing dreams, dreams he was certain did not belong to him and had kept him from getting all but a few hours' rest since the accident were manageable. Tony was accustomed to functioning on relatively little sleep. It was the constant, all-consuming fear of transformation that really gnawed at him.

Tony sighed. Bruce was right; it was harder when he was tired and he was so very tired. If anything, the mishap in the workshop today was evidence of that. Tony sensed he wouldn't be able to resist another transformation like the one he had just endured. And god, now Banner actually thought he had a handle on the Hulk. Tony touched the place in his chest where the arc reactor usually sat, feeling skin and bone under his fingers. It was so far from the truth that it hurt. He didn't have control at all, over anything. Not with any certainty.

He couldn't endure it any longer.

He'd tried so hard to do it Bruce's way: keeping his temper, avoiding caffeine, not drinking, trying to meditate, even though Tony hated it and thought it was stupid. But despite these efforts, he felt his already tentative control over the Hulk slipping away as the days passed. If he could just get a decent night's sleep it would help, maybe, but there was no guarantee. So he poured all his energy into the machine, thinking that if he built it quickly enough, it wouldn't matter and he'd be back in his own body before the monster became uncontrollable. But now he simply didn't know how long it would take to get it working. It might take days, maybe even a week, maybe _more_, depending on how badly the control box had been damaged. Tony didn't think he could hold on that much longer without letting the Hulk out.

Tony trusted his design of the Hulk-resistant room, but transforming here in the city was not an option. He sensed he really needed to let loose in order to tire the Hulk out, and that wasn't happening in the basement of Stark Tower. Asking Bruce to go up north so he could transform without destroying anything important had been his last idea. But Bruce had been right; SHIELD would have been all over them. It would have been a disaster.

He buried his face in his hands. If he transformed, though, it _would _be a disaster. Realistically, there was no way he wouldn't damage the tower if he went green. Pepper was safe in Washington, but how would she feel if Tony was once again responsible for destroying their home? They always had Malibu, he supposed, but Stark Tower was Bruce's home now, too. Oh god, _Bruce_. The physicist was right; if Tony went green, the fallout would be catastrophic for him. Even SHIELD wouldn't be able to smooth it over if the Hulk accidentally killed some innocent bystander or a tower employee. Whatever happened would be pinned on Banner and he would have to leave New York. Tony grimaced and the Hulk rumbled at his distress. Tony swallowed hard. He couldn't let that happen. He would not be responsible for driving his friend out of his home, or worse, back on the run.

He couldn't transform again. That was certain. The consequences were too great.

Tony studied his borrowed hands. There was another way; a way to cut the wire to the ticking time bomb that was the monster in his head. He'd thought about it with increasing frequency as the days passed after the accident, and he grew increasingly exhausted.

Bruce had discovered the transformations were physically triggered by adrenaline in the early days of his search for a cure. He couldn't stop that, but with Tony's help and resources, he had managed to synthesize a drug that blocked it from the receptors responsible for initiating the transformation. Just a few milligrams and Bruce couldn't hulk out until it wore off. They'd even tested it, sneaking off to a remote island in the Pacific to try to make Bruce go green. All he got was sunburned. It worked.

Obviously, the physicist insisted on keeping what little of the drug they had left in a special safe in his lab. It was too dangerous to risk falling into the wrong hands. Only Banner, not Tony or even Barton, had the combination. They hadn't even _spoken_ about it in months. Tony sighed. Bruce thought he was the only one who had access, and Tony was cruel enough to let him think that. It wasn't true. He had an emergency override, a back door, which would allow him to bypass any security in the tower. Tony had ultimate control over all the systems, including everything in Bruce's lab.

Tony steepled his fingers and rocked forward so his elbows rested on his knees. Accessing the lab and even the safe was not a problem, but at what cost? Tony didn't have many moral qualms anymore, but the idea of breaking into Banner's lab gave him pause. It was common knowledge that the scientist spent more time there than anywhere else in the tower. Barton said it was because it made him feel safe. To break into his lab and steal the drug…well, the violation of Bruce's trust would do some serious damage to their friendship.

It wasn't like he could just ask Bruce about it, though. Tony knew the physicist would refuse and then he would be on guard for any of Tony's efforts to acquire it. No, it was much safer just to inject himself and beg forgiveness later. He could do it. He had to do it. It was the only way he could be absolutely positive that he wouldn't transform again.

Tony glanced out through one of the penthouse's large windows over the city. He didn't really see the view. The idea of Pepper's sad-but-resigned eyes and a Banner-free tower made his heart twist uncomfortably. He couldn't risk it. There was too much at stake for it all to be riding on his feeble ability to control the Hulk. He was Tony Stark, and Tony Stark would cut that wire without hesitation. He got to his feet. JARVIS said Banner was still in the workshop, so it was safe to head to the lab.

It took him three tries to enter the lab code because his vision was drifting in and out of focus again. Tony glanced warily over his shoulder and pushed the door open. The musical jingle of the chimes Bruce had hung over the door made him jump. The chimes were intended to keep Tony from sneaking up on the physicist. He glared upward at them malevolently as he slipped inside, his conscience prickling. JARVIS automatically brought the lights up, and the controlled chaos of Banner's lab resolved out of darkness.

The safe was hidden in the floor near Bruce's desk. Tony edged around a lab bench and dropped into his chair. He swiveled from side to side uncertainly, biting his thumb for a moment, before pressing a series of seemingly unrelated keys on Bruce's keyboard. The floor retracted, revealing a small safe. Purportedly, it would hold up even in a bomb blast. Tony worried his thumbnail. There was no going back from this. Bruce was going to be _beyond_ furious.

Tony took a deep breath. So be it. There was too much at stake. He couldn't risk it. At least Bruce would be furious in New York. He couldn't leave, not until they'd finished the machine. He'd cool off by then, right?

"JARVIS," he said aloud, the sound of _Bruce's_ voice instead of his own making him jump. It was weird to be in here by himself. "Activate emergency override two thirty-five."

"_Voiceprint not confirmed. Further authorization is required."_

"Authorization code Stark epsilon delta twelve sigma seven gamma two."

"_Authorization confirmed. Emergency override activated."_

He held his breath for a moment. The lab hummed to life all around him, computers coming up, the fume hood kicking on, the whine of the vacuum pump on the mass spec increasing in pitch. Tony only had eyes for the safe. The safe door clicked and opened with a pneumatic whine. A set of three small syringes were inside, carefully packed into a rack needle-side up.

"JARVIS, make sure you shut all this stuff down when I leave."

Tony reached inside and lifted one. They were filled with viscous yellow liquid. Absently, he dabbed his split lip with his sleeve. He transferred the syringe to his teeth and pushed one sleeve up past Bruce's elbow. The Hulk rumbled his disapproval. Tony ignored him. He looked down at the syringe. What was left of his conscience begged him to visualize Bruce's face when the scientist found out about Tony's betrayal. But somehow the only thing he could remember was the way Natasha's wary eyes used to follow Bruce around the first few weeks they had all lived in the tower.

He'd show her. He'd show them all. Tony was doing the right thing, not just for him, but for everyone. He gritted his teeth and jammed the needle into a vein.

The wave of nausea as the drug took hold almost sent Stark to his knees. He stuffed the syringe into one of the biohazard containers Bruce kept around just in case and staggered into the hall. He slumped against the interior of the elevator and stabbed a key. The glass felt refreshingly cool where it contacted his hot skin. When he got back to the penthouse he would have to manually erase all traces of his presence in the lab. Then he could sleep.

Tony closed his eyes as he rode upwards. He was doing the right thing. Banner would get over it, eventually.

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_Please review! It's always awesome to hear from readers! :)_


	11. Chapter 11

_A/N: Better late than never! Here, have an extra long chapter! :) Many thanks to all who have followed, favorited, and reviewed! Especially huge thanks to RedTigress of The Beta Branch for all her help and beta reading!_

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**Entangled States**

Chapter 11

Bruce Banner yawned as he shuffled into the lab the following morning, clutching a steaming mug of coffee. He wanted to get caught up on some email before he returned to the workshop for another troubleshooting attempt. Bruce had spent most of the night working on the machine, but so far he had been unable to identify the fault that had caused the explosion and Tony's subsequent near-Hulk experience. He sighed as he set down his mug. It was thoroughly frustrating.

He brought up his email without sitting down. The first message was nothing interesting; just the automatically generated instrument status report JARVIS sent him every twenty-four hours. Bruce went to archive it, but one of the plots caught his eye. There was an anomalous spike in the temperature logs. Banner's eyes narrowed slightly and he enlarged the graph. JARVIS continuously monitored the room temperature in his lab because some of his instruments worked best if they were kept at a constant temperature, and some were sensitive even to the slight rise caused by body heat. According to the log, room temperature had spiked for approximately twenty minutes.

Someone had been in his lab.

"JARVIS," the physicist said aloud. The fact that it was Tony's voice in his ears no longer phased him. "Who was in here last night?"

"_I have no record of anyone entering or leaving for the last twenty-four hours, Dr. Banner."_

Puzzled, Bruce brought up the entry logs himself. He scanned through the records. Sure enough, there were no entries at all for the last few days. That made sense at least; Bruce had been busy in the workshop.

"Run a diagnostic on the thermometers, please," he ordered JARVIS.

"_All sensors are fully functional to within 0.05 degrees Celsius."_

He clicked ahead to view the plot in real time. It showed they were in the middle of a similar spike; probably because Bruce was in the lab. Bruce worried his lower lip with his teeth, hating the prickle of Tony's goatee on his skin. "Show me the security footage from last night for that twenty minute period."

Video winked to life on various monitors. It was plain that nobody was in the lab, or even coming in or out. He was about to chalk it up to a malfunction when he noticed something strange. In the video, his glasses were sitting on his desk. Bruce glanced over. No glasses. Of course not; Tony had them.

Bruce bit his lip again. He had, however, left his glasses in that exact spot one night two weeks ago. He remembered because he'd had to come down to find them before reviewing a paper. A cold, tight feeling began to invade his stomach. The security footage had been switched; last night's playback replaced by an old file. It was a very old trick, and it had nearly fooled him.

Someone had been in his lab.

Bruce took a deep breath, ignoring the sear of pain from his lungs. He held it for a count of ten and exhaled slowly. The skin and bone around the chestpiece throbbed with every beat. He pulled up the individual power logs for everything in the lab. At first glance, they were all clean. Not just clean, but completely clean, with none of the normal slight fluctuations Bruce expected to see. Someone had wiped them. He blinked with disbelief. The information on the screen did not change. It momentarily blurred out of focus, but he blinked again and it resolved. A gigantic hand seemed to squeeze his ribs, driving the air out of his lungs and contributing to the ache of the arc reactor.

The sense of violation began to mingle with acid anger was bubbling up into his stomach. It was his _lab_. There was something even more personal about it than his apartment. He was safe here, and someone had invaded it without his knowledge or permission. His heart pounded painfully against the magnet, but he was too angry to wince.

It wasn't just _someone_. _Someone_ didn't have access to his lab. _Someone_ didn't have some sort of override that would start up every single one of his instruments and then shut them down again, improperly. _Someone_ didn't just go back and erase every trace of his presence in JARVIS' records, so Bruce couldn't see who it was.

It was Tony. It had to have been Tony. He was the only one with the requisite knowledge of his systems and the nerve to use it. Bruce felt sick. Why would Tony break into the lab? He had access; he could just walk in. Why come in and then try to erase all evidence that he had been here?

Bruce sank into his desk chair. He leaned forward and squeezed his temples. His elbow brushed something and something small rattled down to the floor. Wearily, he reached down and picked it up. It was a thin, elongate plastic cap. Bruce frowned. It looked familiar somehow, sort of like a cap for a syringe-

Oh _no_. How could he be so stupid? The inhibitor serum.

The realization punched him in the gut. Bruce had nearly forgotten about it; his temporary biochemical solution to the Hulk. He'd been very keen to develop it at first it, envisioning the inhibitor as an occasional respite from having to keep the Hulk in check. However, when he and Tony had started testing it, it had become apparent it wouldn't be a respite after all. Bruce had kept the more disturbing side effects to himself, letting Tony believe that the inherent risk of not being able to Hulk out in an emergency or in self-defense was the reason he stopped testing it.

_That_ might have been a colossal mistake. He muttered a curse under his breath. Tony was supposed to understand and now he was _cheating_. It was a stupid selfish thought and Bruce pushed it away angrily.

His fingers flew to the keyboard and keyed in the combination for the safe. The exhaustion. Asking to let the Hulk out. The pieces all fit the same green puzzle. He _knew_ should have incinerated it. He held his breath while the locks disengaged, hoping against hope that Tony, _Tony of all people_, didn't betray him so thoroughly. He yanked the safe door open roughly.

A syringe was missing. Bruce swore under his breath. He jumped to his feet, violently pushing the desk chair away. It hit the window with a clatter. He slammed one fist down onto his desk. He closed his eyes and took another deep breath, growling at the pain. With that, he turned on his heel and went to find Stark.

The billionaire was in his penthouse. Bruce barged right in. Tony was sprawled on the couch, a gaudy silken bathrobe thrown over the previous day's clothes. For an instant, Bruce was shocked by his haggard appearance. Tony's hair was thoroughly tousled, and there was a slight flush about his cheeks. He looked like he hadn't slept in a very long time. But then Bruce remembered he was angry with Tony.

"What were you doing in my lab last night?" Bruce demanded without preamble. His hands automatically became fists at his sides. He forced his fingers apart.

Tony glanced up from his Starkphone. "Was I in your lab last night?"

Bruce smiled painfully. "You, uh, cleared the autolog, but you forgot the temperature logs. Some of the instrumentation is sensitive enough to drift with body heat. You know that."

"How sloppy," Tony said, and the coolness of his voice, Bruce's voice, was maddening. Bruce felt the control on his temper slip another bit. "Who says it was me?"

"Clint would have used his own code and he couldn't have deleted the logs," Bruce said. He watched Tony's expression intently, trying to read him through the blur of his own features. "The recycled security footage was a nice touch," he added bitterly.

Tony looked dismissively back at his phone. "Fine. Yes, I was in the lab last night."

Burning anger roiled in his stomach. Bruce gritted his teeth against it. Tony was deliberately baiting him, trying to draw off his anger over the serum. "Why?"

"I needed something."

"And you couldn't just ask?" Bruce hissed. Tony studied his fingernails as if bored, but Bruce could tell he was also on edge. They both knew what he was upset about, much as Tony tried to feign innocence. "You had to go behind my back?"

"You would have said no," Stark scoffed without looking up.

"You don't know that." They both knew it was a lie, but Bruce told himself that he would have at least heard Tony out.

"Fine. I took a short cut."

The control on his temper was evaporating quickly. Bruce could feel his body beginning to shake. He tried to will himself to relax. "By _breaking into my safe_? By stealing my work?"

"Technically, I didn't break in. I used a master access code to override all the security," Tony said nonchalantly, but his face had paled. "Perks of, you know, being the owner. And the designer. And the programmer."

Something hot was pressing from behind Bruce's eyes. Blood roared in his ears. He tried to take a deep breath, but his heart was pounding painfully against the arc reactor. He started to try to smother the anger, but he suddenly thought, why? Why bother? He didn't have to worry about the Other Guy coming out. And now neither did Tony.

So Bruce Banner allowed himself to do something he had not willingly done in years. He lost his temper.

"Tony, I trusted you! You promised I would- I mean, my work would be secure!" Bruce cried, internally cringing at the slip of his tongue that belied his deepest fears. Infuriatingly, Tony didn't say anything. He paused for a moment, fumbling for words while he trembled with rage. "It's _experimental!_"

Tony raised an eyebrow at him. "So I wanted to see if it worked. So what?"

"Of all people you should understand why I'm unhappy about you using experimental anything on my body." Bruce's voice cracked a little; he couldn't help it. "We never finished testing it; we don't know what the long-term effects might be and you just…"

"Whose fault is that?" Tony interrupted, stabbing a finger at the furious physicist. Instead of going on the offensive he tried to be reassuring. "It'll be fine; I was directly involved in its creation."

"I locked it up for a reason. I stopped experimenting for a _reason_!"

"You're paranoid," Tony said, waving one of Bruce's hands dismissively. "Nobody can get in to the tower without us knowing. That hasn't changed."

"It's not just that! I know the inhibitor sounds like a great thing, but it's dangerous, Tony."

As usual, the engineer ignored his concerns. He cocked his head to one side as if to study Bruce. "You're right," he announced. "I really don't like you when you're angry."

Bruce shot him a murderous look. If Tony thought his pathetic attempt at humor was going to diffuse the situation, he was very wrong. "I can't _believe_ you! I trusted you and you went behind my back. You _stole_ from me. "

"Hey, that formula is technically half mine. We worked together, remember?"

"Do you have any _idea_ what you've just done?" Bruce exclaimed.

"I'm doing us both a favor. No more worry. No more accidents or interruptions."

Bruce wasn't expecting Tony to apologize, but he wished his friend would at least acknowledge that he'd done something wrong. "It doesn't make him go away," Bruce told him, pinching the bridge of Tony's nose with exasperation. "The Hulk won't leave you alone. It just keeps you from transforming. And now you won't even have that safety valve of knowing you _can_ transform if it comes down to it."

Tony shrugged. "Takes the anxiety out of the equation."

"But you've been doing so well!" There was more than a little disappointment in Bruce's voice. He told himself that it was normal, not totally selfish, to want someone else to understand what he went through on a daily basis.

"Well? This is _well_?" Tony snapped. "Bruce, he's ripping me apart! I haven't slept in days-"

"That's normal!" Bruce shouted, a hundred memories of his early days as a monster roaring back with hurricane force. "I thought I was going to lose my mind for months but I got through it! I could have helped you, Tony. If you asked, if you'd ever bothered to ask, you'd know that! The inhibitor is supposed to be a last resort, not, uh, uh, a shortcut!"

He hit a nerve. Tony slammed his phone onto the table and Banner jumped. Stark sprang to his feet, his anger blazing through Bruce's eyes. He was trembling a little. Bruce took an instinctive step back, but his eyes were still safely deep brown and his skin was not going green. The inhibitor drug was working and the scientist in him couldn't help feeling a little prickle of pride at the success of his work. "It was the last resort! I did everything you said, I _tried_-"

"What if something happens?" Bruce exclaimed. In a flash of green-tinted memory he saw Iron Man falling helplessly through a great rent in the sky. "What if there's another attack? _You can't transform_. If you get hurt, the Hulk won't be able to save you or me. Do you even realize the risk you're taking?"

"Nothing is going to happen."

The physicist squeezed his temples. "You took all of it, didn't you?" he asked anxiously. "It's enough to keep you from transforming for _weeks_! Anything could happen!"

It was Tony's turn to take a deep breath. When he spoke, his voice was flat with forced control. "Bruce. It's going to be fine. It gives us more time to finish the machine."

Despite Bruce's best efforts, the old fears were clawing out of his psyche and spilling out of his mouth. He lowered his hand. "What about Ross? What about AIM? Or HYDRA? All it takes now is some chloroform or a knock on the head and you wake up strapped down to some table in a lab or worse. Tony, you're…I'm completely vulnerable like this!"

Tony bristled at the word. "Sucks, doesn't it?" he spat.

Bruce blinked. "Is this some stupid way of getting even? Because if it is, I swear, if-" He couldn't come up with a worthwhile threat. Suddenly Bruce was seeing red again. Tony was supposed to understand. "Goddamn it, Tony, it's not like I asked you to do anything I don't do myself!"

The engineer looked away. "Yeah, well, I'm not you," he replied.

There was a note of pain in his reply, but Bruce was too angry to care. "I can see that," the physicist snarled. He suddenly wanted to hurt Tony for what he had done; somehow retaliate for the pain of his betrayal and the reawakening of all Bruce's old fears. His eyes narrowed and he lashed out viciously at the engineer. "Steve was right. You never think about the consequences. You just take the easy way out as soon as you can."

Tony recoiled as if Bruce had actually hit him. "Easy?" he cried. His face, Bruce's face, had gone very pale. His voice rose to a frustrated shout. "Nothing about this is _easy_! I am not going to let this turn into another witch hunt for you because I couldn't keep it together!"

His soft eyes widened with horror and he choked to a halt. Clearly Tony had said more than he'd intended to say. Bruce lowered his hands a little and stared at his friend incredulously.

"What?" he asked. His voice really did crack this time, but Bruce did not care. Anger and betrayal warred in his chest with a horrible sensation of guilt that _he_ might have driven Tony to risk using the inhibitor. The words of his warning to Tony seemed burnt into his psyche. _I'll have to leave New York!_ _If you transform, if you smash up Midtown, I'm the one who'll have to leave! _ He swallowed hard. "This…is this about the other night?" Bruce choked.

There was a flash of pain in Stark's eyes. Bruce had the fleeting impression he desperately wanted to say something. Tony's jaw clenched tightly shut. He turned on his heel and retreated into the penthouse. A few seconds later, Bruce heard a door slam after him.

The physicist did not go after him. He slumped onto the arm of the couch and ran his hands through Tony's short hair several times. His chest ached fiercely and he knew it wasn't just from the arc reactor. He massaged the skin around it anyway and took a half-deep breath. Suddenly he had to get away; he had to get out of the tower before he burst. Bruce strode towards the balcony, simultaneously hating Tony for betraying his trust and loving him for his loyalty.

The twin positioning indicators (really, glorified bracelets) Tony used to call his armor were sitting on the low table near the balcony door. Bruce grabbed them without thinking and walked outside. Cool breeze teased at his shirt tails. It felt refreshing against his hot face. He slipped the bracelets on and pressed the button, just like he'd seen Tony do a hundred times.

Lights flashed and there was a faint beeping sound. He nearly jumped out of his skin when the armor flew up behind him with the roar of thrusters. It slid over and around his body like some sort of high tech carapace, forming a barrier between Bruce and the world. It was weirdly soothing.

He flexed his ankles to activate the thrusters as soon as the faceplate slammed shut and the HUD winked to life. It was easier to get into the air this time, he thought, as he twitched his wrists to get the repulsors going. He blasted out across the city, out over the ocean at full thrusters.

It was so quiet, he thought while he rocketed over the water. Inside the helmet, the only sounds were the occasional _whirr_ of JARVIS adjusting the suit's control surfaces and the sound of wind rushing past his covered ears. He was so alone, so gloriously alone out there. It was just Bruce, no Tony, no Hulk intruding his thoughts. He couldn't remember the last time had had been alone. He looped and twisted through the air, no particular destination in mind, simply enjoying the thrill of flight.

After an hour or two of this, Bruce didn't exactly feel better. He had the same tired, drained feeling he used to have after a run. He sighed as he banked back towards the city; his breath causing little eddies of air to buffet his face inside the helmet. He hadn't done it in ages; run just to run or to blow off steam. That had ended with his life in the favela. More recently he would have hidden in his lab, burying himself in data until he forgot everything else. The thought of his violated sanctuary made his stomach twist uncomfortably and his temper prickle.

He cut the thrusters and dropped onto the landing pad at Stark Tower. He hated what Tony had done, but even Bruce had to admit that his heart might have been in the right place. Besides, there wasn't anything he could do to prevent it now. It was going to take time for Tony to earn back his trust, but Bruce had collaborated with people that he liked (and trusted) far less than Tony Stark before.

Now that he was a bit more familiar with the "car wash" (Tony's name for the armor disassembly, not his) process, the armor came off much more easily. Bruce had to admit he was reluctant to let it go. But Bruce had to face Tony at some point, and he wasn't cruel enough to do it in the armor. He replaced the position indicators on Tony's bar and headed for the elevator. JARVIS was kind enough to inform him that Mr. Stark was in the workshop. But Bruce found himself hesitating at the door.

He didn't want to go back.

It was a horrible thought. It was a blasphemous thought. Hastily, Bruce pushed it from his mind. Guilt prickled at his heart. He took as deep a breath as he could manage and pushed the workshop door open. For a split second, he saw Tony look up hopefully before he hid himself in his work again.

"This is not me forgiving you," Bruce said bluntly. He joined Tony at the machine and pulled up the schematic file on the nearest computer. "I am still very angry, Tony, but obviously I can't do anything about it now. Let's finish this damned thing and switch back. Our…issues can wait until then. Am I clear?"

Tony shrugged coolly, but Bruce could tell he was relieved. The engineer reached for his ever-present bottle of painkillers and wrenched off the top. Bruce studied him. Tony looked sick, he thought. Pale skin, dark-circled eyes, his hands were trembling, and he kept blinking as if something bothered his eyes.

Bruce sighed. "Tony, I might be mad, but I do still care. What's wrong?"

"It's nothing," Tony said as he morosely surveyed the interior of the empty painkiller bottle. "The Hulk. Just some headaches. And some not sleeping. I don't know how you deal with the headaches. Really, it's fine."

"I don't get headaches," Bruce observed. "Not constantly, anyway. And usually not related to the Hulk."

"Oh," Tony said. He looked away. His cheeks, Bruce's cheeks, were a little flushed.

"Are you sick?" Banner asked, point-blank. A cold knot began to congeal in the pit of his stomach.

"It's nothing, just a cold," Tony started.

"Tony," Bruce interrupted, but the other man ignored him. Bruce suspected he was so relieved that the scientist was not shouting at him that he didn't want to stop speaking, just in case Bruce changed his mind.

"Nothing to worry about. Timing could have been better. Not very nice of your body to do that while I'm visiting."

"Tony!" Bruce said sharply. The inventor blinked and looked at him. "I don't get sick."

"Don't be ridiculous," Tony retorted with a touch of irritation. "_Everyone_ gets sick. Everyone gets colds."

The little hairs on the back of Bruce's neck began to prickle. He hadn't been ill in years; why should that change now? Unconsciously, he traced over the knuckles of one hand with the opposite thumb. "Tony, I mean it. I don't get sick. It's a Hulk thing."

Something about his tone finally made it through Tony's skull. Stark paled. "Then what the hell is this?"

* * *

_Please review! :)_


	12. Chapter 12

_A/N: After far too long, an update! As always, thanks for the follows, favorites, and especially t__he reviews. Extra big thanks to RedTigress and Nonyvole of The Beta Branch for betaing this massive thing. Enjoy your extra long chapter, everyone! :)_  


* * *

**Entangled States**

Chapter 12

"I sleep in _one_ morning," Clint Barton grumbled from his perch on the worktable, "and everything goes to hell."

The archer had entered the workshop later than usual that day, choosing to catch up on a little sleep before checking in on the geeks. When he had arrived downstairs, he'd walked right into a shouting match between Stark and Banner. Banner was trying to convince Stark to let him stick him with a needle. This was highly unusual, as Banner hated needles and was not a _real_ doctor, as Stark vociferously and repeatedly pointed out. Banner had retorted that he knew what he was doing, he only hated needles when he was on the receiving end of them, and that after Tony's behavior of the previous night, he owed Bruce some cooperation if they wanted to find out why he was getting sick. Clint eventually sorted out the situation: Bruce acquired his blood sample, and Tony grudgingly explained why Banner was pissed at him. Thus far Clint had managed to resist the urge to deck Stark for the shit he had pulled in Bruce's lab. But only just.

Banner was out in the hall now, pacing back and forth. It bothered Clint to see the scientist so worked up. They had been waiting all day for the results of the blood tests he had carried out. Things had to be pretty serious if Banner was willing to risk letting a sample of his irradiated blood out of his sight, Clint thought. He seemed to be having an animated phone conversation while he paced. The fingers of his free hand kept rubbing together, as if he was trying to continue his usual nervous gesture one-handed.

"How did you possibly think that would end well?" the agent shot at Stark with some heat. Maybe he'd get an honest answer out of Tony now that Bruce was safely out of earshot.

"I didn't," Tony retorted without looking up, seemingly unrepentant. His sleeves were pushed up above Banner's elbows, and a bandage across the crook of one of them showed where Bruce had prevailed in drawing blood. Stark adjusted a resistor before continuing. "I'm not sorry, Barton. I made the right choice and everyone is safer for it. I won't apologize for that."

The agent rolled his eyes. Privately, he thought Tony had done the right thing by using the drug. The real problem was that his methods had driven a wedge between Stark and Banner at a time when they most needed to be able to trust each other. Not to mention there was the inevitable psychological fallout for the skittish physicist that Clint now got to handle. He sighed. "But, Christ, Stark, you know better than anyone how he is about that lab…"

Tony reached for a soldering iron. Even though he wasn't looking at Clint, the agent could see a flicker of pain in his eyes. "The benefits outweighed the costs."

"Maybe they did, maybe they didn't," Clint retorted, unwilling to let Tony completely off the hook. He glanced at his watch. Banner's anxiety wasn't entirely off-base; they were late getting the test results back to him. But worrying about it wasn't doing any good. Clint glanced at the machine, fishing for a distraction. "How's it going?"

"I'm nearly back to where we started."

"Well that-"

Clint's reply was interrupted by the sound of the door, followed by Bruce's footsteps. It was funny, Clint thought, how his soft tread had the same pattern it did when he was himself, but a slightly different volume now that he was walking on Stark's feet. He strode over to the nearest monitor and dropped into the chair. His cell phone was no longer in his hand. He clicked something and swiped what looked like a series of charts and tables onto the screen. Stark looked up.

Bruce's bright eyes rapidly scanned the data. He ran a hand across the arc reactor in his chest, absently tapping a meaningless pattern on the hard surface under his shirt. His eyes stopped. The skin around them crinkled. He scanned a particular spot once, twice. It wasn't good, whatever it was. The color drained from his face.

"What, Bruce?" Tony asked. Like Clint, he had been watching the scientist closely. Unlike Clint, he had gone pale himself.

"You need to see this."

Stark dropped his soldering iron and went to look over his shoulder. Bruce pointed out something on the screen. Stark squinted at it. Bruce's glasses were hanging from the collar of Tony's shirt. Banner detached them and handed them to the billionaire without looking away from the screen.

"You were right," Tony breathed. There was nothing victorious about the statement. He sounded almost…scared? Clint's own eyes narrowed. They both seemed to have forgotten the agent's presence.

The physicist shook himself like he was coming out of a trance. Clint recognized his serious, slightly pained expression even through Stark's features. "There's nothing else it could be, Tony," he added quietly. "They couldn't isolate anything that would cause this heavy of an immune response."

"How long do we have?" Stark asked grimly.

"Functional time? At this rate, a week. Maybe less in your case." Bruce pinched the bridge of his nose. He didn't continue until he lowered his hand. "It's possible the inhibitor is making things worse, but I can't be sure."

Tony dropped into a nearby chair and buried his face in his hands. "I just thought it was the Hulk," Stark said, looking up at the scientist. There was a plaintive note in Banner's voice that surprised Clint. He sounded genuinely guilty.

"So did I," Bruce replied heavily.

A cold knot tightened in the pit of Clint's stomach. The hell was going on? He didn't understand what they were talking about, but it was obviously not good. He cleared his throat loudly. Stark and Banner jumped. They _had_ forgotten he was there. "You guys wanna fill me in?" he drawled, trying to sound casual.

Banner glanced at Stark, as if asking permission. Tony nodded infinitesimally. The scientist in Stark's body looked more worried than Clint had seen him since the accident. He licked his lips and said slowly: "Our bodies are each rejecting the foreign consciousness. That's what's making Tony sick. My immune system is attacking his, uh…mind." He glanced up at Clint. "But it's not just him. It's happening to me, too."

The little hairs on the back of Clint's neck prickled ominously. "What's that mean, Bruce?" the agent asked.

"I'm, uh, not exactly an expert in this sort of thing. But essentially…our bodies will try to attack the invading force, the opposite consciousness, until the invader is destroyed."

Clint was no expert either, but he could read between the lines well enough. Well, shit. Sounded like it was time to circle the wagons. "I'll call Rogers," he volunteered. "We need to fill him in."

* * *

Two hours later the Avengers were all collected in Stark's workshop, gathered around Bruce's favorite monitor. Tony had protested this arrangement vehemently until Bruce pointed out that if they stayed in the workshop Tony would be able to keep working on his rewiring while Bruce explained the situation to Natasha and Rogers.

Rogers frowned at the data spread across the display. He rubbed his chin thoughtfully and glanced back at Bruce. "I still don't understand, St-, um, Banner. Why is this happening?"

"My body doesn't recognize…uh, Tony's mind," Bruce explained patiently. "It thinks it's being invaded. It's like when you catch a cold and your body attacks the virus. You get sick. Except this time, there's nothing to attack. It can't attack a foreign consciousness, not directly, but that doesn't mean it won't try. Our bodies are essentially turning against themselves."

Tony kept his eyes determinedly anywhere but on his teammates, but Clint had noticed a feverish glitter in them. The engineer kept silent while Banner spoke. Clint wondered how much of it was due to exhaustion versus shame.

"So what's going to happen to you…guys?" Steve asked, looking between Bruce and Tony.

Bruce squeezed his temples wearily. "I've been asking a lot of people a lot of hypothetical questions about exactly that. Near as I can tell, we'll both experience a pronounced cognitive decline with the increasing immune system response, which will likely terminate in a coma and, well…" Bruce glanced up at them from under Tony's hand, leaving the ominous sentence unfinished.

"Death," Stark cut in.

Three pairs of eyes turned to Bruce for confirmation.

Banner sighed. "I was hoping to put it a little less brutally, but yes."

The knot in Clint's stomach twisted uncomfortably. It was safe to say none of them had anticipated _that _outcome as a result of the accident. Silence fell for a few moments while they absorbed the bad news. Ever practical, Natasha spoke first. "How long do you have?" she asked, the suggestion of a concerned frown on her lips. "And how long do you need?"

"It's difficult to say exactly," Bruce said, with an anxious glance at Tony. "Something about the Hulk sort of enhances my immune system. That will almost certainly accelerate the…decline. I estimate less than a week. There's no way to treat it, either, if Tony's experience is anything to judge by. We have to switch back, or we'll both die."

"But _you _can't die," Steve said, with his usual tact. He levered himself off the workbench he was leaning against to stand upright. Clint suppressed a groan, and he knew without looking that Natasha's eyes were rolling skyward. "Wouldn't you, I mean, your body, just…hulk out?"

Barton had to admit he'd been wondering the same thing himself, but he'd been hoping to ask Banner about it privately. Tony's eyes shifted guiltily to the floor. He hunched over the machine so no one could see his face. Bruce glanced at him and sighed. "Even if it were that simple, which I highly doubt," he told them, "it's not possible. Tony can't transform."

"_What?" _Rogers and Natasha said at the same time.

"Tony decided that instead of keeping the Hulk in check by controlling himself, it would be easier to use a drug we developed," Bruce said, the slight bitterness in his voice betraying his continued anger with Stark. Out of the corner of his eye, Clint saw Stark's fingers clench tightly on the edge of the table. "It inhibits the transformation by blocking adrenaline receptors."

Steve raised an eyebrow, and Clint suddenly had the impression that he guessed there was more to the story than Banner was letting on. But his response was surprisingly diplomatic, given Rogers' usual propensity to jump on Stark whenever he had the opportunity. "I didn't know that was possible, Banner."

Natasha shot Clint an accusing look. Clint gave her his best _who, me?_ expression. He'd been just as blindsided by this as she had. Apparently she believed him, because she shifted her irritation to Banner. He swallowed and looked at the floor. "Why haven't you mentioned this drug before?" the assassin demanded.

Stark looked up at her, Bruce's eyes flashing with sudden anger. "I wasn't aware you had to be personally informed of everything we do, Romanoff," Stark snapped, immediately rallying to Banner's defense. Natasha bristled, but Steve spoke up before Clint could intervene.

"Ban- _Stark's_ right; this isn't the time," Steve said flatly, his tone making it clear he would tolerate no further argument. "I'm sure Banner had his reasons." Natasha's mouth pressed into a thin line, but she said nothing further. The supersoldier's eyes flicked back towards Banner in Stark's body. "What can we do to help, Bruce? SHIELD might be able-"

Bruce shook his head. "No, Steve. Not yet." Tony shot him a questioning look, and Bruce took a deep breath. Stark's fingers worked together anxiously in his lap. "Not unless both of us become, uh, incapacitated. Then, and _only then_, inform SHIELD. Please."

Rogers looked between the scientist and the engineer. "Well, I'm sure it won't come to that, Bruce," he said confidently. "You'll get it done."

* * *

The atmosphere in the workshop changed dramatically after Banner's discovery. The good-natured bickering that Clint was accustomed to hearing had lapsed into an urgent silence, and there was a feeling of desperation that had not been present before. Stark and Banner were both keenly aware that their lives depended on their work. Unfortunately there wasn't much the archer could do about it. Nat thought he was crazy to hang around, but Clint's presence evened both Stark and Banner out so he stayed. It killed Clint to sit on his hands and wait, but there wasn't much else he could do.

Banner had become unusually quiet, seeming to withdraw into himself as the pressure mounted. He was clearly ill, but physically he was still better off than Stark. He seemed to hunch inward even more than usual, gingerly moving around the arc reactor. Clint knew it was hard on him to watch Stark's decline, not only because they were friends, but because it was essentially a preview of the symptoms Bruce would be experiencing in a few days. The hunted look was starting to come back into his eyes. Once or twice Clint caught him staring longingly across the workshop at Tony's armor.

Stark's condition was deteriorating rapidly. At first he tried to hide it through the sheer force of his personality, but he didn't have the energy to maintain the act for long. There was nothing Tony could do to hide his fever-bright eyes or the sickly flush of his cheeks. Despite his growing weakness, Stark worked as if driven by demons. Clint got the impression they were seeing the layer of Tony that was tempered in a cave in Afghanistan. His desperation to beat the clock was palpable. The appearance of each new symptom set off an emotional outburst and a renewed frenzy of activity.

Stark slammed his hands into the table on either side of the disconnected control box. The billionaire had his gaudy bathrobe thrown over his clothes to combat the chills that had recently begun to wrack his body, and he wore a pair of sunglasses ostensibly because the lights of the workshop hurt his eyes. He pushed them up onto his forehead, revealing Banner's glasses underneath. He leaned close to the control box and peered inside. A litany of obscenities filled the air.

Clint looked up with alarm, but Banner didn't even blink. He glanced up from his favorite computer, where he was updating one of his models to incorporate the latest changes Tony had made to the control system. "What, Tony?" he asked patiently.

"It's _backwards_," he snarled. "I did it _backwards_."

"Let me see."

Bruce got up and moved to inspect the area Tony was working on inside the open panel. It just looked like a mess of electronics from Clint's angle. Banner's eyes flicked rapidly between the projected schematic and the actual circuitry. "This is fine. What are you talking about?"

"Oh," Tony said, cocking his head to the side and squinting. "False alarm. I must be seeing things. Or I reversed the schematic in my head. Funny how that works."

Stark's babbling rapidly trailed off into silence. Clint knew that Bruce would have been looking at him over his glasses, if Tony hadn't been wearing them. He continued with his professor stare until Stark squirmed.

"I'm, uh… seeing things," Tony said, his voice cracking slightly. His eyes briefly flickered to something over Bruce's shoulder before finding the physicist again. "Things that aren't there."

Banner hesitated. Even from across the room, Clint saw him shudder. "It's my immune system attacking the visual cortex, I guess," he replied quietly. It took Clint a second to realize that the scientific explanation was meant to be reassuring. "I, uh, haven't gotten to that point yet."

"It's mostly people," Tony continued, at Banner's unspoken question. "But sometimes things." His eyes wandered again, and it suddenly occurred to the archer that Tony's sunglasses had probably served a different purpose than blocking out light.

"Like whom?" Bruce asked quietly.

Stark swallowed. He picked up a pair of pliers and turned them over in Bruce's hands. "My, um…dad. The man who gave me that," he said, gesturing at the arc reactor in Banner's chest. "People I've never met. I don't know their names. Betty, once."

Banner smiled hollowly at her name. He ran his thumb slowly across his knuckles. "Well, that's not so bad."

"Bruce, I've never met her."

A chill ran down Clint's spine. Bruce went very still. He rubbed Stark's hand blearily across his face. "We talked about this, Tony," he said, sounding drained. "The serum blurs the line."

"I know, it's just…"

"There's nothing you can do about it."

"Nothing other than work."

After that, Clint noticed Banner double-checking over all of Stark's work while the billionaire slept. Clint thought the machine was progressing, but it was difficult to be certain. Stark and Banner were several jumps ahead of the archer intellectually, and they had an uncanny ability to finish each other's sentences which made their conversations even more difficult to follow. Tony had finished the modifications to the discharge generator (Bruce preferred _generator_ to _giant cattle prod_), but the system that controlled the electrical discharge was still incomplete. They were doing the best they could, but every hour it became more apparent that their progress might not be fast enough for Tony.

Less than two days later, the mental deterioration Bruce had warned about was becoming more and more pronounced. Sometimes Stark looked down at the complex circuitry of the control box, or a tool in his hand, as if he had never seen it before. On those occasions he would suddenly snap back to himself with a slightly panicked look or an awkward chuckle. As more time passed, the panic transitioned into an irrational anger. His random outbursts of temper even tried Bruce's legendary patience.

"I told you, don't turn down my music!" Stark was whining when Clint re-entered the workshop after a quick nap on the third evening since the diagnosis. He had a brittle tone that the agent had never heard before.

There wasn't any music. Clint glanced at Banner, who shook his head. The physicist shivered, and Clint didn't think it was entirely due to his rising fever. "Sorry, Tony," Bruce apologized patiently. "I won't do it again."

"But I can't focus like this!" Stark cried, a shrill note of hysteria infiltrating his voice. The difference in tone caught Clint's attention as well as Banner's. The soldering iron slipped out of his fingers and rolled to the floor. He winced and clutched at his head. "Not with people watching over my shoulder."

"Nobody's watching over your shoulder," Clint started, but Banner cut him off with a warning look.

"Tony," the scientist said evenly, "why don't you call it a night? I'll finish up."

"There's no time!" Stark spluttered. His eyes darted to the floor, searching for the wayward tool. "There is no time, Banner. Bruce. The Other Guy in here calls _you_ Tony. Whoever you are."

"Tony, please. You need to get some rest."

He took an uncertain step forward, and reached towards the fallen soldering iron. "Dammit I am not dying…as a part time rage monster. I-I am not!" He wobbled drunkenly and looked down at his trembling hand as if it had betrayed him. "Not. Am not." His eyes widened and he shot Banner a panicked look. His throat worked convulsively, but no words came out.

"Tony?" Banner asked hesitantly. "Are you okay?"

Stark was white-faced and shaking. He looked like he was about to-

"Aw, hell," Clint growled as Tony's knees buckled and his body crumpled. He lunged forward and caught Stark before he could hit the floor. Clint carefully lowered him to the ground and rolled him onto his side. Alarming heat radiated from the unconscious man's skin. "Jesus, he's _hot_."

"Tony!" Banner cried, dropping to his knees beside Tony and opposite Clint. The archer glanced at him. He looked very pale around Tony's stupid beard. "JARVIS?"

"_Medical assistance is on the way, Dr. Banner."_

"Stark. Tony!" Clint shook Stark's shoulder gently, but he was unresponsive. He pressed two fingers to Stark's neck, searching for a pulse. It felt thin and rapid through his burning skin.

The archer leaned back on his haunches. There wasn't much they could do until the medics showed up from downstairs. Bruce seemed frozen in place, looking terrified. His gaze was riveted on Tony. There was a feverish glint in Banner's bright eyes that Clint did not like at all, but once again, there wasn't much he could do about it.

When the medics finally arrived, they packed Stark up on a stretcher and moved to take him to the elevator. Barton had retreated a few meters to give them some space, dragging Bruce with him. They would take Stark down to medical and check him out. Natasha would come up with some plausible lie to satisfy the doctor. As long as she had Captain America's reluctant backup, Clint knew nobody would rat them out to SHIELD. Bruce moved to follow them, but Clint grabbed him.

"Banner," Clint said. He got no response. Banner looked downright traumatized, Clint thought. Well, it had to be pretty weird to see your own body comatose like that. He gave the scientist a little shake. "Banner!" he snapped loudly, and Bruce jumped. He was trembling under Clint's fingers. His skin felt hot too, though not as hot as Tony's.

"But I have to-" he started desperately, watching over Clint's shoulder as they pushed Tony into the hall.

"No," Clint said firmly. "We're staying here."

"What?" Bruce protested, twisting in Clint's grasp. "But it's- I can't, it's-"

"Bruce. With Stark down you're the only one who can get the device working. That's the only way to cure this thing, right? Get you two swapped back?" Clint explained. "We need you- _he_ needs you to figure that out now."

Bruce's eyes darted to the machine. "But-" Bruce started again, and this time Clint anticipated what he was worried about.

"Steve and Natasha will keep an eye on him; you don't have to worry about the blood thing."

The scientist let out a long, shuddering breath. "Okay," he said. He slumped a little in Clint's grasp, and the archer released him. "Okay. I…I can do that."

They had no news of Stark for several hours. Bruce sat in silence in Tony's usual spot, looking overwhelmed and a little forlorn. Clint kicked his boots back and forth a little from his perch on the table beside the scientist.

"Y'know, Banner," Clint drawled, tiring of the depressing quiet, "I do know my way around a schematic."

Bruce glanced up at him through Stark's dark-circled eyes. "How much do you know about Leonardo Da Vinci?" he asked in a dull voice.

Clint raised an eyebrow at the _non sequitur_. The healing skin around his stitches itched and he resisted the urge to scratch. "Uh, _Mona Lisa_ guy? He painted stuff?"

Bruce looked down at his hands. "Da Vinci was a brilliant inventor, but he was paranoid. He thought someone would try to steal his work. He used mirror writing to hide it," he explained, sounding drained. It might be Stark's voice, but it was Banner's professor tone. The scientist was grasping for normalcy in the midst of chaos. "Tony's the same way."

"He writes backwards?"

"He doesn't use standard notation," Bruce said with a sigh. "He never has. Apparently we have Bobby Richardson to blame for that particular neurosis. He stole Tony's third grade science project."

The agent raised an eyebrow. "Wait, as in _Senator_ Bobby Richardson?"

Bruce managed a hollow chuckle. "The same. Thanks for the offer, though."

Clint couldn't help grinning. Finally, his pocket buzzed. He reached down to extract his phone. He had a message from Natasha that read "outside."

"Back in a sec," Clint told Bruce.

He stepped out into the hall. Natasha was waiting for him. It was good to see her after hanging around just the geeks for so long, even if the circumstances sucked. A faint line of worry creased her face. Clint cut to the chase. "Stark?" he asked, dreading the response.

Natasha sighed. She brushed a stray strand of hair out of her face. The line of worry deepened. "Not good," she said grimly. "They say he's…in a pretty bad way." Clint's heart sank. She looked down at her fingernails. "Pepper's flying up from Washington. Rogers thought she should know."

Clint rubbed a hand tiredly across his eyes. It was a big step for Rogers to contact Pepper. Natasha studied him with intelligent green eyes. There was a hint of fear in them. "Clint," she started, but he knew what she was going to say before she said it.

"Banner says he can't transform. If you want details, ask him," Clint snapped, more sharply than he'd intended. "Quit worrying about it. We have bigger problems."

He realized he had been harsh and he shot her an apologetic look. But she recognized the stress in his tone and she didn't get mad. Instead, her face softened slightly. "How is Bruce holding up?"

Clint sighed again. "He's hanging in there, but I don't know for how much longer."

"Can he do it?" Natasha asked evenly. There was another question hidden in the seemingly innocuous statement; a question if SHIELD needed to get involved.

Clint glanced through the glass into the workshop. Banner's head was in his hands. "I hope so."

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_Please review!_


	13. Chapter 13

_A/N: Hi everyone! Apologies for not replying to reviews for the last chapter; real life went bonkers and I just couldn't get it done. It's all back under control now, so this time I'll be much better about replying! Many thanks to all reviewers, you helped me get through this difficult chapter. Also thanks to Red Tigress of The Beta Branch for her mad beta skills and putting up with my angst. We're always looking for new writers/readers at TBB; check my profile for details! Without further ado...  
_

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**Entangled States**

Chapter 13

Bruce counted two potential exits from the workshop; three if you counted one of the windows by way of the Iron Man armor. He cupped his prickly chin with a hand and leaned his elbow on the table. Really, there was only one plausible exit. The fire escape didn't count because it was alarmed and Bruce didn't know the override. The armor was less than subtle. That left the main door, and Clint was between him and it. There was no way he could escape without anyone seeing.

Bruce blinked. His vision slid back into focus and he realized was staring at the armor. Again. He gave himself a mental shake. He didn't need to escape. He _chose _to be here. He _wanted_ to be here. Bruce wasn't going to fly away from anything. "Knock it off, Banner," the physicist muttered to himself.

He flicked ahead to the next schematic and gingerly picked up Tony's soldering iron. If he moved too suddenly it sent his head throbbing horribly for hours, and it was already difficult enough to concentrate without that. He'd give up trying to control the headaches or the ever-rising fever because none of the painkillers or antipyretics he took seemed to help. He shivered constantly in spite of the two sweaters he wore to combat the chill of the workshop. His whole body ached, the area in his chest around the arc reactor in particular. The metal casing felt cold inside his chest. Somehow it seemed to suck the warmth from his body.

Carefully, he began to lay out the circuit Tony's plans outlined. Bruce knew he was making progress, but he had stopped tracking it because every time he looked at the red and green wireframe model of the complete machine (discharge unit plus control box), he panicked. He had to take it one step at a time or the task became overwhelming.

The finished device would simultaneously replicate the electrical discharge that each Bruce and Tony had experienced individually. Frankly, the system was appallingly complex. The device had to recreate the exact conditions of an electrical explosion that had lasted mere fractions of a second. It took into account every variable: the resistance of Tony's armor and skin, energy loss in air over the distance from ground zero to their bodies…everything.

_If_ it worked.

Bruce sighed. This was precisely the situation that he had feared from the moment he'd woken up in Tony's body; it all coming down to him. At first, he'd been able to drown his fears with Tony's confidence. This was Tony's element; he lived for engineering challenges like the device. But now Tony was gone and he wasn't coming back. Sure, the computer simulations Bruce had done using Tony's specifications worked just fine, but everyone knew things tended to work a lot different virtually than in real life.

Besides, Bruce still didn't understand why they had even survived the explosion. How could he be certain he was recreating the right effect if he didn't even know what it was? There were so many factors, so many little uncertainties that could affect the outcome that he simply did not understand.

His grip tightened on the soldering iron. Bruce had built himself a machine once, and used it. He'd thought he'd understood it; he'd been so very certain he'd understood every single solitary variable. He'd been so confident that he tried it on himself. He was wrong. It turned him into a monster.

The monster. The Hulk. The Other Guy. Knots of anxiety tightened in Bruce's stomach at the thought of the Hulk. He should try to relish these last quiet hours in his head. _Don't think about it_, he told himself firmly. He couldn't face that, not yet.

Despite his best efforts, his heart was pounding under the electromagnet and his hands were shaking again. Bruce got up to pour himself a cup of coffee (really, Clint needed to cut back on his coffee consumption before he gave himself an ulcer) and wrapped his hands around the mug. He probably wouldn't even drink it, but he liked the feeling of the heat against his palms. He would never understand why the gradual thermal equilibration of the warm ceramic with his hands was so soothing. Bruce closed his eyes and tried to imagine the feeling of flight. It was his only escape now, because he couldn't focus long enough to meditate and his chest hurt too badly to do breathing exercises.

When he was calmer, he opened his eyes. He ignored the dark shapes dancing on the periphery of his vision. The hallucinations had started just over twenty-four hours ago as minute flaws in Bruce's field of vision. They weren't particularly bothersome, except when he caught a glimpse of motion in the corner of his eye and it startled him. It was funny how that worked; how his symptoms differed from Tony in that regard. Maybe his body's supercharged immune system had a stronger effect on the visual cortex than Tony's. Maybe Bruce was just lucky.

He had to admit to feeling a little disappointed that they never became corporeal, though. There was a small twisted part of him that had actually looked forward to the potential of seeing Betty again, even if she wasn't real. That was better than nothing.

Unlike Tony, Bruce had a fairly easy time ignoring the hallucinations. At least until he nearly destroyed the control box by accidentally installing the wrong resistor because his eyes misread a label. He broke down at that point and with JARVIS' help, translated all of Tony's plans into something more standard so Clint could double check his work. Tony would be mad, but Bruce didn't care. It was better to be safe than sorry.

The archer was sprawled on the workshop couch, snoring softly. Bruce eyed him enviously. He couldn't really blame Clint for nodding off. It was tedious work (even if your life depended on it), and they had already worked straight through the night. At least one night. Time was becoming a more and more fluid concept as his fever rose and Bruce had lost track.

A sudden flicker of motion in the corner of his eye made him jump. Bruce glanced around, but he saw nothing but his reflection on the shining surface of the monitor. He relaxed and moved to pick up his soldering iron. Finally his lagging brain caught up. The little hairs prickled on the back of his neck. He hadn't felt anything; not surprise, not the weird jolt in the pit of stomach he felt the first time he saw Tony's bright brown eyes staring at him out of the mirror and every time since. Sometime in the past day it had ceased to be Tony's reflection and now it was his. The speed with which he had internalized this new self-image terrified him.

Bruce shuddered. He had to see Tony. The physicist glanced at Clint, who was still safely sleeping. Bruce couldn't bring himself to explain the situation. He carefully got to his feet, grabbing the edge of the workbench to steady himself. His body trembled with weakness and he wasn't exactly steady on his feet, but his footsteps were still soft, and he managed to slip out without waking the archer.

He couldn't work up the nerve to go inside Tony's room. Medical always made him nervous and the sight of tubes and monitors hooked up to his body was disconcerting. Bruce hunched outside with his hands in his pockets, looking in through the window. One of the nurses brushed past him into the room carrying something white wrapped in a towel. She lay whatever it was across Bru- _Tony's_ chest. Blue fingerprints appeared, surrounded by frosty white halos. A cold pack, Bruce realized. They must really be desperate if they were using ice to try to lower his fever. Just the thought of ice against skin made Bruce squirm. The touch of cool metal or glass when he had to open doors sent chills racing through his body now. But Tony didn't even twitch.

"Bruce?" a soft voice said behind him, and he jumped. Pepper Potts was looking at him, just Pepper now with her hair down around her face and a sad little smile. She clutched a steaming mug in one hand. "What are you doing down here?"

Intellectually he knew it wasn't an accusation, but it felt like one. Bruce swallowed hard. "I, uh…had to…check something," he stammered. She eyed him with a hint of suspicion and Bruce fumbled for a question to stave off her questions. "Is, uh, Rhodes coming?"

Pepper's face fell. "He's stuck doing war games in Korea right now. Looks like it's just us."

"Oh," Bruce said awkwardly. "Sorry."

He turned back to look at the semi-lifeless form in the bed. Bruce's heart twisted uncomfortably, but not for the reason he'd expected. It wasn't Tony lying there; it was him. It was Bruce Banner. But he didn't feel much of anything looking at his own comatose body, other than a vague, nearly instinctual dislike. Why would he ever go back to that?

Pepper must have mistaken his guilty silence for distress, because she squeezed his arm in a comforting way and slipped past him into the room. She took a seat near the head of the bed and gently ran her fingers through Bruce's graying hair. Somehow this peaceful image disturbed him more than anything else he had seen in Medical, and Bruce fled back to the workshop without another word.

It was a mark of how tired Clint was that he didn't wake when Bruce stumbled back into the workshop. Bruce himself was beyond exhausted, but his mind was reeling and there was no way he'd be able to sleep now. He didn't know what to do. He couldn't meditate; he couldn't even manage deep breaths or any of the other things he would have normally done to calm down. Numbly, he sagged back into his usual chair and resumed working.

His focus evaporated after less than an hour. It was so unfair, he thought while he wired the finished circuitry into the control box. Tony got to go back to being Tony, with everything that entailed, and Bruce had to go back to being Bruce and he didn't want to. He wanted to be able to go out and keep his head to himself, to have a woman in his life who loved him, to never have to run scared from anything ever again.

Why would he willingly give all that up? Why would he ever go back to that pathetic, monstrous life? Bruce looked at the machine and suddenly he hated it. He wanted to smash it to pieces. He looked down and a heavy wrench was clenched in his hand. He could do it; one blow in the right place and the fragile control system would be destroyed. The machine would be destroyed.

Then he would never have to go back.

Horrified by the sudden temptation, Bruce dropped the wrench. He snatched his hands away from the tool as if it would burn him. He couldn't bring himself to do it, could he? He eyed the wrench again before jumping up and stuffing it into a tool cabinet well out of his line of sight. He slumped back into his chair, panting. What was he _thinking_? Bruce had to go back. His life depended on it. _Tony's_ life depended on it!

Clint jerked awake at the commotion. "Wha's that all about?" he demanded blearily.

"Nothing," Bruce lied. It hurt deep in his chest when he spoke. The sheer absurdity of the situation suddenly hit him. He had spent years running from the Hulk and now that he was finally free, he was fighting with all his strength to go back. It was absolutely insane. He wasn't sure if he was going to laugh or cry. His subconscious decided both and he could feel his eyes sting and a hysterical giggle pass his lips.

He leaned forward onto his elbows and pressed his palms into his eyes. The gesture didn't do much to relieve the renewed throb inside his skull, but it hid his face from Clint. It wasn't real, he told himself desperately. The emotional fluctuations were a symptom of his uncontrollable fever, nothing more. He clung to the scientific explanation, but rational thought was quickly drowned by the scream of his instincts. He let out a shuddering breath and tried to focus on the feeling of flight. It didn't work.

"Banner?" Clint asked, and Bruce looked up. The agent had moved to sit across the worktable from him. Suddenly Bruce was hyperaware of the creases of worry around his dark-circled eyes. "What's going on?"

"Nothing," Bruce repeated, but his voice cracked and betrayed him. He cursed himself mentally. "I…I just need to get out of here."

The agent spitted him on a pale stare, but Bruce stubbornly refused to elaborate. "Fine," Clint said, sounding resigned. "C'mon, let's get you upstairs-"

Bruce flinched away from the proffered hand. His temper flared for no reason. "I can make it myself," Bruce snapped. Barton's eyes narrowed, but he backed off.

Clint's eyes bored holes in his back all the way out of the workshop and into the elevator. Once he was safely out of the agent's line of sight, Bruce sagged against the wall of the elevator. He just managed to keep his body from sliding down the glass to the floor. Unwanted memories suddenly surged through him, memories of green rage crushing against his eyes, green fingers picking through his thoughts, of suffocating in his own head, and made his pulse quicken in the elevator. He gripped the interior railing until his knuckles went white.

He didn't want to go back.

He feebly tried to brush the thought away, but it had already taken hold and he no longer had the strength to root it out. The words echoed through his skull in time with every beat of his heart, every throb of his head. He didn't want to go back. He couldn't go back.

Bruce fell into bed, dizzy with exhaustion. But even sleep held no respite. He woke shivering in cold sweat and tangled bedding after what felt like a mere handful of hours, his heart pounding horribly from a half-remembered nightmare. The dull sunlight penetrating the window shades hurt. His vision had taken on a surreal quality: edges too sharp, colors slightly too bright. The pain in his chest forced him to take quick, shallow breaths, and when he managed to stand he felt lightheaded. His heart felt fast and fluttery against the remnants of his ribs and the unyielding electromagnet.

When Bruce next came to himself, he was in the workshop, staring blankly at the Iron Man armor with no memory of how he had got there or what he was doing. He blinked slowly, once, twice. There was another completed circuit lying on the worktable in front of him. He cocked his head slightly to one side. There was a little purple mark in the corner that meant Clint had inspected the circuit. Bruce didn't remember any of it. He picked it up and began wiring it into the machine.

His eyes wandered and he saw the archer out in the hall. Clint had his cell phone to his ear and a very serious expression. His eyes drifted to Bruce and the physicist realized that Clint's conversation was about him. Probably with SHIELD. Bruce should care, but it took too much energy. He sagged back into his chair and squeezed his temples.

"Bruce," a quiet voice said. A familiar, female voice. His hands dropped to the table top with shock. Bruce's heart jolted under the electromagnet as he looked up into Betty Ross' soft blue eyes.

She looked just like he remembered: her warm smile and thick dark hair pulled up into the bun that meant she was working in the lab instead of lecturing. His throat felt suddenly constricted. He swallowed, trying to find words, to say anything. He'd wanted to see her so badly and now she was here.

Betty's smile grew. Somehow she seemed to understand. She always understood. Her lips parted as if to say something. Her hand reached towards Bruce's own-

Iron fingers bit into the muscles of his upper arm and shook him hard. "Banner. Banner! Bruce!"

Startled, Bruce whipped around and looked into Clint Barton's worried face. "No!" Bruce cried. He turned back, but Betty was gone. He wrenched his arm out of the archer's grasp and rounded on him with disappointed fury.

The archer took a step back. Somehow Clint managed to look scared, worried, and horrified all at the same time. "Whoa, man," he said in a tense voice. "It's me! Relax." He held his hands up in a non-threatening gesture, but there was a tension about his body that puzzled the physicist.

Bruce suddenly realized he'd raised his fist to strike Barton. He made himself lower his hand to his side. The fingers were still tightly clenched. His head pounded abominably and he winced. His knees wobbled and he realized he had somehow jumped out of his seat. He dropped back into his chair before he could collapse. "What did you do that for?"

Clint shot him an incredulous look. "Bruce, you're _crying_."

"What?"

The agent looked profoundly unsettled. "You were staring into thin air and crying, man."

That was absurd; Bruce didn't cry. But there was something in Clint's tone that made Bruce reach up to brush his cheek. His heart nearly stopped; there was moisture there. He had no memory of crying. He hastily scrubbed a hand over his cheeks to remove any trace of tears, embarrassed. There was a horrible lump in his throat. Why was he crying? _He didn't cry_.

He suddenly wanted to hear Betty's voice again, so badly it hurt. She had been about to say something before Clint had interrupted. Deep down, Bruce knew she was a just a twisted memory dredged up by his subconscious because his brain was melting-

His blood went cold. Auditory hallucinations. Just like Tony, right before he had collapsed. He was into the final stage. He _was_ dying, Bruce realized with a giddy hiccup of fear. It mingled with an odd sense of contentment. There was actually some tiny sick part of him that was glad.

Bruce shuddered again and this time the motion of his ribs made the arc hurt like hell. At least he wouldn't have to deal with it for much longer. One way or the other. He half-heartedly tried to massage the area around it and reached up to swipe to the next circuit diagram. Nothing happened. Bruce frowned slightly. He tried it again to the same result. Puzzled, he pulled up the master wireframe, the one that tracked his progress. It was all green. There weren't any more schematics. It was done.

"What, Banner?" Clint asked.

He wasn't happy. He wasn't relieved or excited or any of the things Tony would have been. All Bruce felt was dread pooling in the pit of his stomach. It was going to happen. He was going back. He reached up and snapped the access panel on the control box shut.

He took as deep a breath as he could manage and tried to let it out slowly. His hands were already starting to shake. He shot Clint a fearful glance. "It's finished."

Things began to happen very quickly, too quickly for what was left of Bruce's mind to process. Clint was everywhere, giving instructions to JARVIS, calling down to Steve and Natasha, looking for Pepper. Bruce himself seemed to drift through a surreal fog while he disconnected the machine and followed Clint and Steve while they dragged it downstairs. He still couldn't quite believe it. He was _trying_ to go back to the Hulk.

Someone found him a chair outside of Tony's room in Medical. He sat there watching Clint and Natasha try to wrestle the machine and a second bed inside. Now Clint was swearing because he couldn't find a high voltage electricity conduit in the floor. He ducked outside, carrying a long coil of thick electrical cable. Bruce seized the archer's wrist as he passed.

"It's happening?" the scientist asked dazedly. Part of him still hoped everything was all just a horrible, horrible nightmare and that he would just _wake up_. "This…this is all really happening?"

Natasha took the coil of cable and moved down the hall. Clint's eyes were sad. "Yeah. It's really happening." Bruce released his wrist. The agent straightened up ran his hands through his hair several times. When he looked back at Bruce, he had retreated behind one of his neutral Agent Barton expressions. "Look, I need you to check the connections on the machine. I think I did it right, but we should double check, yeah?"

"Okay," Bruce replied numbly. Clint offered him a hand up and he accepted it. He swayed on his feet but managed to stumble into Tony's room. Clint hovered for a moment to make sure Bruce wasn't going to collapse before heading after Natasha.

The device looked absurdly large in the small room, jammed into a corner near the second, empty bed. The one that was meant for him. Bruce shivered and tried to ignore it while he examined the connections on the machine. Clint had been paying attention when Bruce described how to dismantle and reset the machine; he found no flaws. Not even on the hastily rigged remote switch, so the device could be safely triggered from outside the room. His eyes kept sliding towards the empty bed.

Soon he would be on it, waiting for the sear of energy that would make him back into a monster. Bruce took a wobbly step backwards, colliding with the door. He could already feel the suffocating acid tide flooding over his mind and his body. He squeezed his eyes shut but the image of the device and the empty bed was seared onto his retinas. Panting, Bruce forced his eyes open and looked out into the empty hall. He made his decision.

He couldn't do it. He couldn't face the Hulk again. He wasn't a hero; he never had been. He wasn't brave or selfless. He was a monster and a coward. He was Bruce Banner and he was going to run away.

He always ran away.

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_Please review! :) I promise I'll write back this time!_


	14. Chapter 14

_A/N: Egads, I'm finally back! Sorry about the massive delay on this chapter, dear readers. I had to take a very sudden, extended trip and writing during it wasn't an option. But now it's back to business as usual! A huge THANK YOU to everyone who read and reviewed during this period! I didn't always get a chance to write back, but I really appreciated it! :) I will put a **trigger warning: suicide** on this chapter._

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**Entangled States**

Chapter 14

The nearest high voltage conduit was farther from Stark's room than Clint would have liked, but the cable was just long enough with some clever maneuvering. The tricky business had been finding a way to splice the cable into it without electrocuting himself or Natasha. Natasha was the one who ended up _doing_ the actual splicing. She wasn't as sleep-deprived or coffee-saturated as he was, so her hands were a lot steadier.

The SHIELD agent glanced impatiently down the hall while she worked, bouncing on his toes to stay awake. He didn't like to leave Bruce alone for long. The physicist's mental state had been steadily deteriorating over the past few days, and after what happened with Stark…well, Clint was worried. It was stupid, he hadn't been gone more than a few minutes; but Banner had been pretty out of it when Clint left. He sighed and squeezed his temples. Terrified, too, although thus far the scientist had been too stubborn to admit it…

"Clint," Natasha said sharply, the sound of his name dragging him out of his thoughts. He glanced down at her. "It's going to be fine."

There was a hint of reassurance under her studiously flat tone. Clint felt the corner of his mouth quirk upward slightly. He must really look like hell if his partner felt the need to verbally reassure him. "Yeah. I know."

Natasha gave him the ghost of a smile and snapped the protective cover shut over the conduit. "Let's get this over with."

Clint gave her a hand up and they headed back towards Stark's room together. "All hooked up," he announced as he rounded the corner. "Let's get the show on the road, man."

There was no response. Barton stopped dead in his tracks. Beside him, he heard Natasha inhale sharply. The chair was empty. Banner was _gone_.

Clint's heart jolted nervously against his ribs. Through the window, he could see Pepper sitting beside Stark's bed. Steve Rogers stood awkwardly behind her, his arms folded over his chest. Bruce wasn't with them. He looked down the hall, opposite the way he and Natasha had come. Nothing. Natasha strode down towards the elevators and looked in either direction down adjacent hallways. She looked back at Clint and shook her head.

The hell was going on? Clint swallowed his initial panic and rapped his knuckles on the glass. Maybe Steve knew. The solider looked up instantly, his eyes narrowing when he noticed Clint's expression. Pepper glanced up briefly, but Rogers said something inaudible and she looked back down at Tony's comatose body. Steve squeezed her shoulder in a comforting way before joining Barton and Natasha in the hall. "Where's Banner?" he asked Clint, glancing around with surprise. "Stark's a lot worse. We need to move on this, now."

Well, that settled that. Clint's heart sank. "Was here when I left," he replied. "You didn't see him?"

"Bruce was gone before Ms. Potts and I got here, then," Steve said. Stark must really be in a bad way, because Captain America looked uncharacteristically grim. "I guess I thought he went with you."

Natasha rolled her eyes at them both. "JARVIS," she said coolly, "where's Dr. Banner?"

To Clint's surprise, JARVIS' reply sounded a little…flustered. _ "I'm sorry, Agent Romanoff, but that information is restricted."_

"What?" Steve demanded, glancing up at the celling with exasperation. "Since when?"

"_That information is also restricted, Captain Rogers."_

Clint swore under his breath. Somehow the paranoid scientist had figured out how to keep JARVIS from tracking his movements. Stark's recent betrayal had probably prompted Bruce to invoke whatever override he had. Goddamn it, Clint should have never let him out of his sight. The last thing they needed right now was a Stark-style meltdown.

"JARVIS, ping the comms in Banner's lab and apartment," he ordered the AI, rubbing a hand over his freshly healed forehead. He honestly doubted Bruce had the strength left to stagger that far into the tower, but if he did, it made sense for him to flee to somewhere he felt safe.

"_At once, Agent Barton," _the AI replied. After a few moments he chimed in again with, _"I'm sorry, sir, there is no response from either location."_

"Shoot," Clint muttered. Out of the corner of his eye, he saw Natasha's lips purse into a thin line. Well, he should have guessed it wouldn't be that easy…

"You checked this floor?" Rogers asked.

"Not many places to hide here. Too many people who would ID Stark," Natasha observed. "Besides, Banner hates Medical."

She had a point. "Sounds like we'll have to do this the old-fashioned way," Steve said, instinctively trying to take charge of the situation. "I'll call security; we'll start with the lab and Banner's apartment."

The thought of how a delirious Bruce might react to being found by armed security made Clint's stomach twist uncomfortably. "Look, Rogers, we need to keep this in the family. He's scared and he's not entirely with it right now. You send a bunch of thugs after him and-"

His plea was interrupted when the door to Stark's room opened. Pepper Potts slipped through it, seemingly attracted by their raised voices. She looked about as tired as Clint felt, with large dark circles under her eyes and wisps of hair haloing her face. "What's going on?"

Rogers shot Clint a dirty look over Pepper's head. The archer resisted the urge to roll his eyes. Pepper was more than capable of taking care of herself, but Steve always had to be so damn chivalrous. The soldier forced a smile before speaking up. "Please, Ms. Potts-"

Pepper's eyes narrowed dangerously and he ground to a halt. Steel threaded into her soft voice. "Just tell me, _Captain_ Rogers."

Rogers gulped. Natasha intervened before he could stammer out a response. "Bruce is missing," she told Pepper, her voice carefully neutral.

"_What?_" Pepper breathed. Her face went very pale under her freckles. She glanced desperately between Clint and Natasha. "But we need- where- but what about Tony?"

"Pepper, we'll find him," Clint said.

Pepper took a deep breath. With a last glance into Tony's room, she quickly pulled herself. "Where have you looked?" she asked them in her CEO voice.

"We only just realized he was gone," Steve said. "Barton and Romanoff think we can rule out this floor."

"_Ms. Potts,"_ JARVIS intoned.

"Not now, JARVIS," Pepper said absently. She went to a monitor on one of the walls and brought up a schematic of Stark Tower. She marked _Medical_ in red and glanced over at Clint. "Have you tried his lab?" she asked, frowning slightly.

"There wasn't any response on the comm," Clint said. "We should probably go check it anyway, though."

"_I am afraid I must insist, Ms. Potts," _JARVIS cut in._ "The Mark VI has just been activated."_

The AI's words didn't mean anything to Clint. He ignored the mechanical voice and ran his hands through his dirty hair, thinking. His mind felt slow, dulled by exhaustion. What was Bruce doing? If he could figure that out, maybe he could guess where the scientist had gone. Clint knew he was scared…hiding maybe? But-

"The Mark VI?" Pepper said blankly, interrupting his thoughts. "Who-"

Mark VI. Mark VI. A memory flashed across his mind's eye: Bruce gazing longing across the workshop at something red and gold. Clint blinked. Mark VI. It was a _suit_. _The suits_. Clint had caught him staring at the suits several times with increasing frequency over the past few days. "It's _Bruce_," he said aloud.

All eyes were suddenly on him. Clint squeezed his palms against either side of his head, trying to force his fatigued mind to grind into gear. There wasn't anyone else with access to the suits; just Stark and he sure wasn't going anywhere. Not even his biometrics would be able to keep Banner out…the guy was walking around in Stark's body.

"Barton?" Rogers asked. Out of the corner of his eye, Clint saw Pepper's fingers tighten anxiously on the soldier's arm.

Clint ignored him. So Bruce was scared; probably nervous about using the machine and all the risks it entailed. Hell, Clint couldn't blame him for that. But why the armor? But what did Bruce want with it? Normally his MO was to just lie low and well, disappear. He wasn't into flashy armor or streaking across the sky at Mach 2-

The pieces fell into place, and the pit dropped out of Clint's stomach. He lowered his hands slowly. Banner might not be about flash or firepower, but he wasn't _Bruce_ at the moment. Bruce Banner might be stuck on the ground, but Tony Stark…Tony Stark could just _fly away_.

"Christ," Clint exclaimed. "He's trying to run."

* * *

Clint's frantic fingers jammed the passcode into the workshop's keypad. God, he hoped he wasn't too late. He didn't want to know what would happen if Bruce somehow managed to get into a suit and Rogers had to bring SHIELD in. The lock clicked and he darted inside.

The overhead lights were out, plunging the cavernous room into near darkness. The white-blue eyes of Tony's armor glowed brightly from their alcove. He counted masks quickly; none of them were missing. One of the suits hung open (the Mark VI, Clint guessed), the motionless pieces dangling like a broken marionette. But they were all still there, and to his knowledge, intact.

"Banner? You in here?" he shouted, his sharp eyes scanning for the scientist. He listened carefully, but the workshop was disconcertingly silent beyond the hum of servers and the quiet _woosh_ of the air-handling system. There was no response.

Clint took a few cautious steps inside. His relief at finding the suits intact was short-lived. A scattering of shining droplets were dribbled across the floor a few yards from the door. He followed the trail to the edge of a workbench, which was smeared with the same shining dark substance. He didn't need to touch it to know it was blood. "Banner?" he called again more urgently. "I know you're here!"

"That…didn't take long," Stark's voice gasped after a pair of tense heartbeats. "Guess- guess I'm not as …subtle as I thought."

The voice came from direction of the armor alcove. Now that Clint knew where to look, he noticed one of the equipment lockers was slightly displaced from the others, as if something had shifted it. He vaulted the bloody worktable and ducked around a cluster of Stark's massive servers. Banner was slumped against the locker; his legs sprawled uselessly before him. The physicist's face was chalk-white around Stark's goatee and shining with sweat in the bluish light cast by the suits. He held one sleeve pressed against the side of his head. Clint noticed the dark stain of blood on his fingers.

"What're you doin' up here, man?" Clint asked the scientist, trying to sound upbeat and failing miserably. His half smile felt stiff on his lips. The hairs on the back of Clint's neck rose as he crouched down between Bruce and the armor. He didn't like putting his back to something with _eyes_. "You've got somewhere to be."

Bruce looked up the archer and tried to smile, but it came across as more of a grimace. He peered out from behind his forearm with a dull, resigned look that reminded Clint of a trapped animal. He suppressed a shudder at the thought. "I wasn't… planning on staying," the scientist panted, looking wistfully over Clint's shoulder at the armor. He glanced sheepishly back at Barton. "But I, uh, can't…stand."

The bloody, finger-sized smudges on the floor and the cabinet nearest Banner revealed where he had attempted (several times) to do just that. Clint's suspicions had been correct; Banner _was_ trying to run. He leaned back on his haunches. Small wonder Bruce sounded exhausted. He let Banner have another moment to catch his breath before he spoke. "C'mon," he said quietly. "Let's get you back downstairs."

Bruce's head lolled limply back against the metal. "No."

"What?"

Banner's eyes closed but he kept speaking; voice thin and feverish. "I knew…I knew you wouldn't just let me go. I-I tried to make this easier for everyone by leaving, but I couldn't. I'm sorry."

Wait, what? This reasoning was certainly a curve ball. How would running make anything easier for anyone? "Bruce, what're you talking about?" Clint snapped, confused.

Banner almost looked ashamed when he looked back up at the archer. "I'm not going back, Clint," he said weakly. "I can't. I can't do it anymore."

Nerves about the process Clint could understand; hell, he would have been freaking out in Banner's place. Trying to run away, he could understand. Bruce was scared and he'd been running so long that it was second nature to him. It made sense that his first instinct would be to _get away_. But Bruce hadn't once mentioned having second thoughts about going back to his body since he and Stark started working on the device, at least in Clint's hearing.

"You're going to do this _now_? " Barton demanded. He bit back a string of frustrated curses. He didn't have time for this. _Tony_ didn't have time for this. Clint pinched the bridge of his nose, trying to hide his irritation. "There isn't another option, Banner. You have to switch back with Stark."

"Who says it'll work?" Bruce exclaimed, his voice cracking a little. He adjusted the position of his sleeve against his temple and grimaced. Clint could see him shivering in the half-light, despite his layers of clothing. "We shouldn't have survived that blast. There's-there's no _evidence_ that shows why we did. How can you be so sure we'll survive it again? How do you know it won't make us into something worse?"

Banner said the last part so quietly that if Clint hadn't seen his lips moving, he wouldn't have known Bruce was speaking. He suddenly had the impression that Bruce wasn't talking about himself and Tony, but that was just crazy. Clint glanced down at the floor. He didn't have a good answer for the scientist. "Well, I got faith in you and Stark," he said uncertainly.

Stark's features twisted with disdain. "That's…nice. A nice sentiment," Bruce said bitterly. "Tell me, how should I factor sentiment into our probability for survival?"

"Bruce, it's gonna be zero if you don't try."

The scientist reached up and squeezed the bridge of his noise. "I'm aware," he said, sounding resigned, yet somehow a little bit…pleased?

A chill went down Clint's spine. He'd seemed lucid enough before, but now Clint was not so sure. "Banner," he said firmly. "Stark can't wait anymore. You need to do this now."

"Clint," Bruce told him gently, with but a vaguely mad conviction that froze Clint's blood, "Tony's gone."

The archer gaped at him for a moment. "He will be if you don't get it together real quick, man," Clint retorted. "He's down there, Bruce, alive, in Medical-"

"That's not Tony," Banner cried, his voice rising shrilly into a near shout. He stabbed a finger at Clint. "That- that- that…_shell _is not Tony!"

Clint swallowed hard. Somehow he knew he wouldn't be able to argue the point. It hadn't been as dramatic as Stark's final breakdown, but there was no doubt in his mind anymore as to Banner's lucidity. He put on one of his neutral agent expressions to avoid alarming the scientist further. Slowly, he extended a hand towards Banner. "Come on, let's get you down to Medical."

"_Don't touch me!" _Bruce shouted, recoiling violently from Clint's hand. He tried to scramble away from the SHIELD agent, but there wasn't anywhere to go. He flattened his body against the metal of the cabinet. Tony's fingers splayed desperately against the smooth floor as if to brace himself. Light glinted off the fresh gash near his temple.

Clint raised his hands in as non-threatening a manner as he could and backed off. Bruce remained tensed as if to flee until SHIELD agent was well out of arm's reach. "Banner- _Bruce_," he pleaded, not caring that desperation tinged his voice. He couldn't think of another way to reach the delirious scientist. "You'll die if you don't go through with this."

Bruce made a noise that sounded like coughing, and Clint realized it was supposed to be a chuckle. He gripped his chest around the arc reactor as if it pained him. There was a hysterical edge in his reply that the archer had never heard before. "_I don't care_. I'm not going back."

"Please, Bruce-"

Something in Banner seemed to snap again. His hands balled into defiant fists. "I'm not going back in there with him!" he shouted, surging forward violently. "I won't do it, not again!"

Clint took a deep breath. He fought to keep his voice even; losing his cool how wasn't going to help anyone. Time was ticking, though, and he really didn't want to find out what would happen if Rogers decided to get involved. He lowered his hands a little and tried again. "Bruce. I know you're scared-"

"No, you don't!" Bruce cried. He let out a little cry of pain and clutched at his heaving chest. "You're all so eager to throw me back to the Hulk but you don't understand what you're asking me to do. None of you do. I can't go back to that! I can't face him again!"

He looked away, gritting his teeth stubbornly. Clint didn't have anything to say. He bit the inside of his cheek. He wanted to do something, _anything_, to help, but he was afraid to get too close in case he unintentionally freaked Banner out worse. He made a sympathetic little gesture, but did not attempt to touch the scientist. Gradually, his friend's ragged breathing slowed. The last outburst seemed to have taken something out of the physicist. He slumped against the cabinet and looked up at Clint tiredly.

The archer rocked back on his heels and rubbed a hand over his mouth. He didn't know what to do. The realization made him feel like someone was twisting a knife in his insides. "What happened, man?" Clint asked, not caring that his voice cracked. "I thought you were done running."

There was the hint of a knowing smile on his lips that suddenly made Clint's blood run cold. "I'm not running," Bruce told him, sounding drained but weirdly _content_. "At least, not for much longer."

Clint stared at him, a question ready on his lips. Bruce almost looked…hopeful. Suddenly he understood. Bruce wasn't running, not really. He was _waiting_. And if he waited long enough-

"What?" Clint cried, horrified. If Banner waited long enough, he was going to die and he was going to take Stark with him. "No. Bruce, you can't-" He choked to a halt. This wasn't happening. This wasn't _Banner_, for Christ's sake! Banner wouldn't do this. Banner wouldn't let his friend just die. "But what about Stark?" Clint demanded.

But Bruce wasn't listening, not anymore. "Trust me, Clint. It's better for everyone this way. He'll be _gone_. The Other Guy won't hurt anyone ever again," he said almost dreamily. "And I won't have to fight anymore."

* * *

_Please review! :) _


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